def test_ring_breaking_detection():
"""
Test the detection of ring-breaking transformations.
"""
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
from perses.tests.utils import createOEMolFromIUPAC
from perses.tests.utils import render_atom_mapping
molecule1 = createOEMolFromIUPAC("naphthalene")
molecule2 = createOEMolFromIUPAC("benzene")
# Allow ring breaking
new_to_old_atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(
molecule1, molecule2, allow_ring_breaking=True)
if not len(new_to_old_atom_map) > 0:
filename = 'mapping-error.png'
render_atom_mapping(filename, molecule1, molecule2,
new_to_old_atom_map)
msg = 'Napthalene -> benzene transformation with allow_ring_breaking=True is not returning a valid mapping\n'
msg += 'Wrote atom mapping to %s for inspection; please check this.' % filename
msg += str(new_to_old_atom_map)
raise Exception(msg)
new_to_old_atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(
molecule1, molecule2, allow_ring_breaking=False)
if not len(new_to_old_atom_map) == 0:
filename = 'mapping-error.png'
render_atom_mapping(filename, molecule1, molecule2,
new_to_old_atom_map)
msg = 'Napthalene -> benzene transformation with allow_ring_breaking=False is erroneously allowing ring breaking\n'
msg += 'Wrote atom mapping to %s for inspection; please check this.' % filename
msg += str(new_to_old_atom_map)
raise Exception(msg)
def test_mapping_strength_levels(pairs_of_smiles=[('Cc1ccccc1','c1ccc(cc1)N'),('CC(c1ccccc1)','O=C(c1ccccc1)'),('Oc1ccccc1','Sc1ccccc1')],test=True):
correct_results = {0:{'default': (3,2), 'weak':(3,2), 'strong':(4,3)},
1:{'default': (7,3), 'weak':(6,2), 'strong':(7,3)},
2:{'default': (1,1), 'weak':(1,1), 'strong':(2,2)}}
mapping = ['weak','default','strong']
for example in mapping:
for index, (lig_a, lig_b) in enumerate(pairs_of_smiles):
print(f"conducting {example} mapping with ligands {lig_a}, {lig_b}")
initial_molecule = smiles_to_oemol(lig_a)
proposed_molecule = smiles_to_oemol(lig_b)
molecules = [Molecule.from_openeye(mol) for mol in [initial_molecule, proposed_molecule]]
system_generator = SystemGenerator(forcefields = forcefield_files, barostat=barostat, forcefield_kwargs=forcefield_kwargs,nonperiodic_forcefield_kwargs=nonperiodic_forcefield_kwargs,
small_molecule_forcefield = 'gaff-1.81', molecules=molecules, cache=None)
proposal_engine = SmallMoleculeSetProposalEngine([initial_molecule, proposed_molecule], system_generator)
initial_system, initial_positions, initial_topology = OEMol_to_omm_ff(initial_molecule, system_generator)
print(f"running now with map strength {example}")
proposal = proposal_engine.propose(initial_system, initial_topology, map_strength = example)
print(lig_a, lig_b,'length OLD and NEW atoms',len(proposal.unique_old_atoms), len(proposal.unique_new_atoms))
if test:
render_atom_mapping(f'{index}-{example}.png', initial_molecule, proposed_molecule, proposal._new_to_old_atom_map)
assert ( (len(proposal.unique_old_atoms), len(proposal.unique_new_atoms)) == correct_results[index][example]), f"the mapping failed, correct results are {correct_results[index][example]}"
print(f"the mapping worked!!!")
print()
def test_ring_breaking_detection():
"""
Test the detection of ring-breaking transformations.
"""
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
from openmoltools.openeye import iupac_to_oemol, generate_conformers
molecule1 = iupac_to_oemol("naphthalene")
molecule2 = iupac_to_oemol("benzene")
molecule1 = generate_conformers(molecule1, max_confs=1)
molecule2 = generate_conformers(molecule2, max_confs=1)
# Allow ring breaking
new_to_old_atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(
molecule1, molecule2, allow_ring_breaking=True)
if not len(new_to_old_atom_map) > 0:
filename = 'mapping-error.png'
render_atom_mapping(filename, molecule1, molecule2,
new_to_old_atom_map)
msg = 'Napthalene -> benzene transformation with allow_ring_breaking=True is not returning a valid mapping\n'
msg += 'Wrote atom mapping to %s for inspection; please check this.' % filename
msg += str(new_to_old_atom_map)
raise Exception(msg)
new_to_old_atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(
molecule1, molecule2, allow_ring_breaking=False)
if not len(new_to_old_atom_map) == 0:
filename = 'mapping-error.png'
render_atom_mapping(filename, molecule1, molecule2,
new_to_old_atom_map)
msg = 'Napthalene -> benzene transformation with allow_ring_breaking=False is erroneously allowing ring breaking\n'
msg += 'Wrote atom mapping to %s for inspection; please check this.' % filename
msg += str(new_to_old_atom_map)
raise Exception(msg)
def generate_vacuum_hybrid_topology(mol_name="naphthalene", ref_mol_name="benzene"):
from topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
import simtk.openmm.app as app
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
m, unsolv_old_system, pos_old, top_old = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
initial_smiles = oechem.OEMolToSmiles(m)
final_smiles = oechem.OEMolToSmiles(refmol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
solvated_system = forcefield.createSystem(top_old)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'])
geometry_engine = FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles], system_generator, residue_name=mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system, top_old)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal, pos_old, beta)
return topology_proposal, pos_old, new_positions
def generate_vacuum_hybrid_topology(mol_name="naphthalene", ref_mol_name="benzene"):
from topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
import simtk.openmm.app as app
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
m, unsolv_old_system, pos_old, top_old = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
initial_smiles = oechem.OEMolToSmiles(m)
final_smiles = oechem.OEMolToSmiles(refmol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
solvated_system = forcefield.createSystem(top_old)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'])
geometry_engine = FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles], system_generator, residue_name=mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system, top_old)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal, pos_old, beta)
return topology_proposal, pos_old, new_positions
def generate_solvated_hybrid_test_topology(current_mol_name="naphthalene", proposed_mol_name="benzene"):
"""
Generate a test solvated topology proposal, current positions, and new positions triplet
from two IUPAC molecule names.
Parameters
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
import simtk.openmm.app as app
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
current_mol, unsolv_old_system, pos_old, top_old = createSystemFromIUPAC(current_mol_name)
proposed_mol = createOEMolFromIUPAC(proposed_mol_name)
initial_smiles = oechem.OEMolToSmiles(current_mol)
final_smiles = oechem.OEMolToSmiles(proposed_mol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
modeller = app.Modeller(top_old, pos_old)
modeller.addSolvent(forcefield, model='tip3p', padding=9.0*unit.angstrom)
solvated_topology = modeller.getTopology()
solvated_positions = modeller.getPositions()
solvated_system = forcefield.createSystem(solvated_topology, nonbondedMethod=app.PME, removeCMMotion=False)
barostat = openmm.MonteCarloBarostat(1.0*unit.atmosphere, temperature, 50)
solvated_system.addForce(barostat)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'], barostat=barostat, forcefield_kwargs={'removeCMMotion': False, 'nonbondedMethod': app.PME})
geometry_engine = geometry.FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles], system_generator, residue_name=current_mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system, solvated_topology)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal, solvated_positions, beta)
return topology_proposal, solvated_positions, new_positions
def generate_solvated_hybrid_test_topology(current_mol_name="naphthalene", proposed_mol_name="benzene"):
"""
Generate a test solvated topology proposal, current positions, and new positions triplet
from two IUPAC molecule names.
Parameters
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
import simtk.openmm.app as app
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
current_mol, unsolv_old_system, pos_old, top_old = createSystemFromIUPAC(current_mol_name)
proposed_mol = createOEMolFromIUPAC(proposed_mol_name)
initial_smiles = oechem.OEMolToSmiles(current_mol)
final_smiles = oechem.OEMolToSmiles(proposed_mol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
modeller = app.Modeller(top_old, pos_old)
modeller.addSolvent(forcefield, model='tip3p', padding=9.0*unit.angstrom)
solvated_topology = modeller.getTopology()
solvated_positions = modeller.getPositions()
solvated_system = forcefield.createSystem(solvated_topology, nonbondedMethod=app.PME, removeCMMotion=False)
barostat = openmm.MonteCarloBarostat(1.0*unit.atmosphere, temperature, 50)
solvated_system.addForce(barostat)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'], barostat=barostat, forcefield_kwargs={'removeCMMotion': False, 'nonbondedMethod': app.PME})
geometry_engine = geometry.FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles], system_generator, residue_name=current_mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system, solvated_topology)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal, solvated_positions, beta)
return topology_proposal, solvated_positions, new_positions
def generate_top_pos_sys(topology, old_oemol, new_oemol, system, positions,
system_generator, map_strength):
"""generate point mutation engine, geometry_engine, and conduct topology proposal, geometry propsal, and hybrid factory generation"""
#create the point mutation engine
print(f"generating point mutation engine")
proposal_engine = SmallMoleculeSetProposalEngine(['CCCCO', 'CCCCS'],
system_generator,
map_strength=map_strength,
residue_name='MOL')
#create a geometry engine
print(f"generating geometry engine")
geometry_engine = FFAllAngleGeometryEngine(metadata=None,
use_sterics=False,
n_bond_divisions=100,
n_angle_divisions=180,
n_torsion_divisions=360,
verbose=True,
storage=None,
bond_softening_constant=1.0,
angle_softening_constant=1.0,
neglect_angles=False,
use_14_nonbondeds=False)
#create a top proposal
print(f"making topology proposal")
topology_proposal = proposal_engine.propose(system, topology, old_oemol,
new_oemol)
#make a geometry proposal forward
print(f"making geometry proposal")
forward_new_positions, logp_proposal = geometry_engine.propose(
topology_proposal, positions, beta)
#create a hybrid topology factory
f"making forward hybridtopologyfactory"
forward_htf = HybridTopologyFactory(topology_proposal=topology_proposal,
current_positions=positions,
new_positions=forward_new_positions,
use_dispersion_correction=False,
functions=None,
softcore_alpha=None,
bond_softening_constant=1.0,
angle_softening_constant=1.0,
soften_only_new=False,
neglected_new_angle_terms=[],
neglected_old_angle_terms=[],
softcore_LJ_v2=True,
softcore_electrostatics=True,
softcore_LJ_v2_alpha=0.85,
softcore_electrostatics_alpha=0.3,
softcore_sigma_Q=1.0,
interpolate_old_and_new_14s=False,
omitted_terms=None)
return topology_proposal, forward_new_positions, forward_htf
def generate_vacuum_hostguest_proposal(current_mol_name="B2", proposed_mol_name="MOL"):
"""
Generate a test vacuum topology proposal, current positions, and new positions triplet
from two IUPAC molecule names.
Parameters
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
from openmoltools import forcefield_generators
from openmmtools import testsystems
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
host_guest = testsystems.HostGuestVacuum()
unsolv_old_system, pos_old, top_old = host_guest.system, host_guest.positions, host_guest.topology
ligand_topology = [res for res in top_old.residues()]
current_mol = forcefield_generators.generateOEMolFromTopologyResidue(ligand_topology[1]) # guest is second residue in topology
proposed_mol = createOEMolFromSMILES('C1CC2(CCC1(CC2)C)C')
initial_smiles = oechem.OEMolToSmiles(current_mol)
final_smiles = oechem.OEMolToSmiles(proposed_mol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
solvated_system = forcefield.createSystem(top_old, removeCMMotion=False)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'], forcefield_kwargs={'removeCMMotion': False, 'nonbondedMethod': app.NoCutoff})
geometry_engine = geometry.FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles], system_generator, residue_name=current_mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system, top_old, current_mol=current_mol, proposed_mol=proposed_mol)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal, pos_old, beta)
return topology_proposal, pos_old, new_positions
def generate_vacuum_topology_proposal(current_mol_name="benzene", proposed_mol_name="toluene"):
"""
Generate a test vacuum topology proposal, current positions, and new positions triplet
from two IUPAC molecule names.
Parameters
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
current_mol, unsolv_old_system, pos_old, top_old = createSystemFromIUPAC(current_mol_name)
proposed_mol = createOEMolFromIUPAC(proposed_mol_name)
initial_smiles = oechem.OEMolToSmiles(current_mol)
final_smiles = oechem.OEMolToSmiles(proposed_mol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
solvated_system = forcefield.createSystem(top_old, removeCMMotion=False)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'], forcefield_kwargs={'removeCMMotion': False, 'nonbondedMethod': app.NoCutoff})
geometry_engine = geometry.FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles], system_generator, residue_name=current_mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system, top_old, current_mol=current_mol, proposed_mol=proposed_mol)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal, pos_old, beta)
return topology_proposal, pos_old, new_positions
def test_simple_heterocycle_mapping(iupac_pairs=[('benzene', 'pyridine')]):
"""
Test the ability to map conjugated heterocycles (that preserves all rings). Will assert that the number of ring members in both molecules is the same.
"""
# TODO: generalize this to test for ring breakage and closure.
from openmoltools.openeye import iupac_to_oemol
from openeye import oechem
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
for iupac_pair in iupac_pairs:
old_oemol, new_oemol = iupac_to_oemol(iupac_pair[0]), iupac_to_oemol(
iupac_pair[1])
new_to_old_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(
old_oemol,
new_oemol,
atom_expr=None,
bond_expr=None,
verbose=False,
allow_ring_breaking=False)
#assert that the number of ring members is consistent in the mapping...
num_hetero_maps = 0
for new_index, old_index in new_to_old_map.items():
old_atom, new_atom = old_oemol.GetAtom(
oechem.OEHasAtomIdx(old_index)), new_oemol.GetAtom(
oechem.OEHasAtomIdx(new_index))
if old_atom.IsInRing() and new_atom.IsInRing():
if old_atom.GetAtomicNum() != new_atom.GetAtomicNum():
num_hetero_maps += 1
assert num_hetero_maps > 0, f"there are no differences in atomic number mappings in {iupac_pair}"
def generate_hybrid_test_topology(mol_name="naphthalene",
ref_mol_name="benzene"):
"""
Generate a test topology proposal and positions for the hybrid test.
"""
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC
mol = createOEMolFromIUPAC(mol_name)
m, system, positions, topology = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
#map one of the rings
atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(mol, refmol)
#now use the mapped atoms to generate a new and old system with identical atoms mapped. This will result in the
#same molecule with the same positions for lambda=0 and 1, and ensures a contiguous atom map
effective_atom_map = {value: value for value in atom_map.values()}
#make a topology proposal with the appropriate data:
top_proposal = TopologyProposal(new_topology=topology,
new_system=system,
old_topology=topology,
old_system=system,
new_to_old_atom_map=effective_atom_map,
new_chemical_state_key="n1",
old_chemical_state_key='n2')
return top_proposal, positions
def test_small_molecule_proposals():
"""
Make sure the small molecule proposal engine generates molecules
"""
from perses.rjmc import topology_proposal
from openmoltools import forcefield_generators
from collections import defaultdict
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
import openeye.oechem as oechem
list_of_smiles = ['CCCC','CCCCC','CCCCCC']
gaff_xml_filename = get_data_filename('data/gaff.xml')
stats_dict = defaultdict(lambda: 0)
system_generator = topology_proposal.SystemGenerator([gaff_xml_filename])
proposal_engine = topology_proposal.SmallMoleculeSetProposalEngine(list_of_smiles, system_generator)
initial_molecule = generate_initial_molecule('CCCC')
initial_system, initial_positions, initial_topology = oemol_to_omm_ff(initial_molecule, "MOL")
proposal = proposal_engine.propose(initial_system, initial_topology)
for i in range(50):
#positions are ignored here, and we don't want to run the geometry engine
new_proposal = proposal_engine.propose(proposal.old_system, proposal.old_topology)
stats_dict[new_proposal.new_chemical_state_key] += 1
#check that the molecule it generated is actually the smiles we expect
matching_molecules = [res for res in proposal.new_topology.residues() if res.name=='MOL']
if len(matching_molecules) != 1:
raise ValueError("More than one residue with the same name!")
mol_res = matching_molecules[0]
oemol = forcefield_generators.generateOEMolFromTopologyResidue(mol_res)
smiles = SmallMoleculeSetProposalEngine.canonicalize_smiles(oechem.OEMolToSmiles(oemol))
assert smiles == proposal.new_chemical_state_key
proposal = new_proposal
def test_small_molecule_proposals():
"""
Make sure the small molecule proposal engine generates molecules
"""
list_of_smiles = ['CCCC','CCCCC','CCCCCC']
list_of_mols = []
for smi in list_of_smiles:
mol = smiles_to_oemol(smi)
list_of_mols.append(mol)
molecules = [Molecule.from_openeye(mol) for mol in list_of_mols]
stats_dict = defaultdict(lambda: 0)
system_generator = SystemGenerator(forcefields = forcefield_files, barostat=barostat, forcefield_kwargs=forcefield_kwargs, nonperiodic_forcefield_kwargs=nonperiodic_forcefield_kwargs,
small_molecule_forcefield = small_molecule_forcefield, molecules=molecules, cache=None)
proposal_engine = topology_proposal.SmallMoleculeSetProposalEngine(list_of_mols, system_generator)
initial_system, initial_positions, initial_topology, = OEMol_to_omm_ff(list_of_mols[0], system_generator)
proposal = proposal_engine.propose(initial_system, initial_topology)
for i in range(50):
#positions are ignored here, and we don't want to run the geometry engine
new_proposal = proposal_engine.propose(proposal.old_system, proposal.old_topology)
stats_dict[new_proposal.new_chemical_state_key] += 1
#check that the molecule it generated is actually the smiles we expect
matching_molecules = [res for res in proposal.new_topology.residues() if res.name=='MOL']
if len(matching_molecules) != 1:
raise ValueError("More than one residue with the same name!")
mol_res = matching_molecules[0]
oemol = generateOEMolFromTopologyResidue(mol_res)
smiles = SmallMoleculeSetProposalEngine.canonicalize_smiles(oechem.OEMolToSmiles(oemol))
assert smiles == proposal.new_chemical_state_key
proposal = new_proposal
def compare_energies(mol_name="naphthalene", ref_mol_name="benzene"):
"""
Make an atom map where the molecule at either lambda endpoint is identical, and check that the energies are also the same.
"""
from openmmtools import alchemy, states
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
from perses.annihilation.relative import HybridTopologyFactory
import simtk.openmm as openmm
from perses.utils.openeye import createSystemFromIUPAC
from openmoltools.openeye import iupac_to_oemol, generate_conformers
mol = iupac_to_oemol(mol_name)
mol = generate_conformers(mol, max_confs=1)
m, system, positions, topology = createSystemFromIUPAC(mol_name)
refmol = iupac_to_oemol(ref_mol_name)
refmol = generate_conformers(refmol, max_confs=1)
#map one of the rings
atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(mol, refmol)
#now use the mapped atoms to generate a new and old system with identical atoms mapped. This will result in the
#same molecule with the same positions for lambda=0 and 1, and ensures a contiguous atom map
effective_atom_map = {value: value for value in atom_map.values()}
#make a topology proposal with the appropriate data:
top_proposal = TopologyProposal(new_topology=topology,
new_system=system,
old_topology=topology,
old_system=system,
new_to_old_atom_map=effective_atom_map,
new_chemical_state_key="n1",
old_chemical_state_key='n2')
factory = HybridTopologyFactory(top_proposal, positions, positions)
alchemical_system = factory.hybrid_system
alchemical_positions = factory.hybrid_positions
platform = openmm.Platform.getPlatformByName("Reference")
_, _, alch_zero_state, alch_one_state = utils.generate_endpoint_thermodynamic_states(
alchemical_system, top_proposal)
rp_list = []
for state in [alch_zero_state, alch_one_state]:
integrator = openmm.VerletIntegrator(1)
context = state.create_context(integrator, platform)
samplerstate = states.SamplerState(
positions=alchemical_positions,
box_vectors=alchemical_system.getDefaultPeriodicBoxVectors())
samplerstate.apply_to_context(context)
rp = state.reduced_potential(context)
rp_list.append(rp)
del context, integrator
assert abs(rp_list[0] - rp_list[1]) < 1e-6
def generate_solvated_hybrid_test_topology(mol_name="naphthalene",
ref_mol_name="benzene"):
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
import simtk.openmm.app as app
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
mol = createOEMolFromIUPAC(mol_name)
m, unsolv_system, pos, top = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(
forcefield_generators.gaffTemplateGenerator)
#map one of the rings
atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(mol, refmol)
#now use the mapped atoms to generate a new and old system with identical atoms mapped. This will result in the
#same molecule with the same positions for lambda=0 and 1, and ensures a contiguous atom map
effective_atom_map = {value: value for value in atom_map.values()}
modeller = app.Modeller(top, pos)
modeller.addSolvent(forcefield, model='tip3p', padding=9.0 * unit.angstrom)
topology = modeller.getTopology()
positions = modeller.getPositions()
system = forcefield.createSystem(topology, nonbondedMethod=app.PME)
n_atoms_old_system = unsolv_system.getNumParticles()
n_atoms_after_solvation = system.getNumParticles()
for i in range(n_atoms_old_system, n_atoms_after_solvation):
effective_atom_map[i] = i
top_proposal = TopologyProposal(new_topology=topology,
new_system=system,
old_topology=topology,
old_system=system,
new_to_old_atom_map=effective_atom_map,
new_chemical_state_key="n1",
old_chemical_state_key='n2')
return top_proposal, positions
def test_molecular_atom_mapping():
"""
Test the creation of atom maps between pairs of molecules from the JACS benchmark set.
"""
from openeye import oechem
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
from perses.tests.utils import createOEMolFromSMILES
from perses.tests.utils import render_atom_mapping
from itertools import combinations
# Test mappings for JACS dataset ligands
for dataset_name in [
'CDK2'
]: #, 'p38', 'Tyk2', 'Thrombin', 'PTP1B', 'MCL1', 'Jnk1', 'Bace']:
# Read molecules
dataset_path = 'data/schrodinger-jacs-datasets/%s_ligands.sdf' % dataset_name
mol2_filename = resource_filename('perses', dataset_path)
ifs = oechem.oemolistream(mol2_filename)
molecules = list()
for mol in ifs.GetOEGraphMols():
molecules.append(oechem.OEGraphMol(mol))
# Build atom map for some transformations.
#for (molecule1, molecule2) in combinations(molecules, 2): # too slow
molecule1 = molecules[0]
for i, molecule2 in enumerate(molecules[1:]):
new_to_old_atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(
molecule1, molecule2)
# Make sure we aren't mapping hydrogens onto anything else
atoms1 = [atom for atom in molecule1.GetAtoms()]
atoms2 = [atom for atom in molecule2.GetAtoms()]
#for (index2, index1) in new_to_old_atom_map.items():
# atom1, atom2 = atoms1[index1], atoms2[index2]
# if (atom1.GetAtomicNum()==1) != (atom2.GetAtomicNum()==1):
filename = 'mapping-error-%d.png' % i
render_atom_mapping(filename, molecule1, molecule2,
new_to_old_atom_map)
#msg = 'Atom atomic number %d is being mapped to atomic number %d\n' % (atom1.GetAtomicNum(), atom2.GetAtomicNum())
msg = 'molecule 1 : %s\n' % oechem.OECreateIsoSmiString(molecule1)
msg += 'molecule 2 : %s\n' % oechem.OECreateIsoSmiString(molecule2)
msg += 'Wrote atom mapping to %s for inspection; please check this.' % filename
msg += str(new_to_old_atom_map)
print(msg)
def generate_solvated_hybrid_test_topology(mol_name="naphthalene", ref_mol_name="benzene"):
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
import simtk.openmm.app as app
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
mol = createOEMolFromIUPAC(mol_name)
m, unsolv_system, pos, top = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
#map one of the rings
atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(mol, refmol)
#now use the mapped atoms to generate a new and old system with identical atoms mapped. This will result in the
#same molecule with the same positions for lambda=0 and 1, and ensures a contiguous atom map
effective_atom_map = {value : value for value in atom_map.values()}
modeller = app.Modeller(top, pos)
modeller.addSolvent(forcefield, model='tip3p', padding=9.0*unit.angstrom)
topology = modeller.getTopology()
positions = modeller.getPositions()
system = forcefield.createSystem(topology, nonbondedMethod=app.PME)
n_atoms_old_system = unsolv_system.getNumParticles()
n_atoms_after_solvation = system.getNumParticles()
for i in range(n_atoms_old_system, n_atoms_after_solvation):
effective_atom_map[i] = i
top_proposal = TopologyProposal(new_topology=topology, new_system=system, old_topology=topology, old_system=system, new_to_old_atom_map=effective_atom_map, new_chemical_state_key="n1", old_chemical_state_key='n2')
return top_proposal, positions
def generate_hybrid_test_topology(mol_name="naphthalene", ref_mol_name="benzene"):
"""
Generate a test topology proposal and positions for the hybrid test.
"""
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC
mol = createOEMolFromIUPAC(mol_name)
m, system, positions, topology = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
#map one of the rings
atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(mol, refmol)
#now use the mapped atoms to generate a new and old system with identical atoms mapped. This will result in the
#same molecule with the same positions for lambda=0 and 1, and ensures a contiguous atom map
effective_atom_map = {value : value for value in atom_map.values()}
#make a topology proposal with the appropriate data:
top_proposal = TopologyProposal(new_topology=topology, new_system=system, old_topology=topology, old_system=system, new_to_old_atom_map=effective_atom_map, new_chemical_state_key="n1", old_chemical_state_key='n2')
return top_proposal, positions
def compare_energies(mol_name="naphthalene", ref_mol_name="benzene"):
"""
Make an atom map where the molecule at either lambda endpoint is identical, and check that the energies are also the same.
"""
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
from perses.annihilation.new_relative import HybridTopologyFactory
import simtk.openmm as openmm
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC
mol_name = "naphthalene"
ref_mol_name = "benzene"
mol = createOEMolFromIUPAC(mol_name)
m, system, positions, topology = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
#map one of the rings
atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(mol, refmol)
#now use the mapped atoms to generate a new and old system with identical atoms mapped. This will result in the
#same molecule with the same positions for lambda=0 and 1, and ensures a contiguous atom map
effective_atom_map = {value: value for value in atom_map.values()}
#make a topology proposal with the appropriate data:
top_proposal = TopologyProposal(new_topology=topology,
new_system=system,
old_topology=topology,
old_system=system,
new_to_old_atom_map=effective_atom_map,
new_chemical_state_key="n1",
old_chemical_state_key='n2')
factory = HybridTopologyFactory(top_proposal, positions, positions)
alchemical_system = factory.hybrid_system
alchemical_positions = factory.hybrid_positions
integrator = openmm.VerletIntegrator(1)
platform = openmm.Platform.getPlatformByName("Reference")
context = openmm.Context(alchemical_system, integrator, platform)
context.setPositions(alchemical_positions)
functions = {
'lambda_sterics':
'2*lambda * step(0.5 - lambda) + (1.0 - step(0.5 - lambda))',
'lambda_electrostatics': '2*(lambda - 0.5) * step(lambda - 0.5)',
'lambda_bonds': 'lambda',
'lambda_angles': 'lambda',
'lambda_torsions': 'lambda'
}
#set all to zero
for parm in functions.keys():
context.setParameter(parm, 0.0)
initial_energy = context.getState(getEnergy=True).getPotentialEnergy()
#set all to one
for parm in functions.keys():
context.setParameter(parm, 1.0)
final_energy = context.getState(getEnergy=True).getPotentialEnergy()
if np.abs(final_energy -
initial_energy) > 1.0e-6 * unit.kilojoule_per_mole:
raise Exception(
"The energy at the endpoints was not equal for molecule %s" %
mol_name)
def __init__(self, molecules: List[str], output_filename: str, ncmc_switching_times: Dict[str, int], equilibrium_steps: Dict[str, int], timestep: unit.Quantity, initial_molecule: str=None, geometry_options: Dict=None):
self._molecules = [SmallMoleculeSetProposalEngine.canonicalize_smiles(molecule) for molecule in molecules]
environments = ['explicit', 'vacuum']
temperature = 298.15 * unit.kelvin
pressure = 1.0 * unit.atmospheres
constraints = app.HBonds
self._storage = NetCDFStorage(output_filename)
self._ncmc_switching_times = ncmc_switching_times
self._n_equilibrium_steps = equilibrium_steps
self._geometry_options = geometry_options
# Create a system generator for our desired forcefields.
from perses.rjmc.topology_proposal import SystemGenerator
system_generators = dict()
from pkg_resources import resource_filename
gaff_xml_filename = resource_filename('perses', 'data/gaff.xml')
barostat = openmm.MonteCarloBarostat(pressure, temperature)
system_generators['explicit'] = SystemGenerator([gaff_xml_filename, 'tip3p.xml'],
forcefield_kwargs={'nonbondedMethod': app.PME,
'nonbondedCutoff': 9.0 * unit.angstrom,
'implicitSolvent': None,
'constraints': constraints,
'ewaldErrorTolerance': 1e-5,
'hydrogenMass': 3.0*unit.amu},
barostat=barostat)
system_generators['vacuum'] = SystemGenerator([gaff_xml_filename],
forcefield_kwargs={'nonbondedMethod': app.NoCutoff,
'implicitSolvent': None,
'constraints': constraints,
'hydrogenMass': 3.0*unit.amu})
#
# Create topologies and positions
#
topologies = dict()
positions = dict()
from openmoltools import forcefield_generators
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
# Create molecule in vacuum.
from perses.tests.utils import createOEMolFromSMILES, extractPositionsFromOEMOL
if initial_molecule:
smiles = initial_molecule
else:
smiles = np.random.choice(molecules)
molecule = createOEMolFromSMILES(smiles)
topologies['vacuum'] = forcefield_generators.generateTopologyFromOEMol(molecule)
positions['vacuum'] = extractPositionsFromOEMOL(molecule)
# Create molecule in solvent.
modeller = app.Modeller(topologies['vacuum'], positions['vacuum'])
modeller.addSolvent(forcefield, model='tip3p', padding=9.0 * unit.angstrom)
topologies['explicit'] = modeller.getTopology()
positions['explicit'] = modeller.getPositions()
# Set up the proposal engines.
proposal_metadata = {}
proposal_engines = dict()
for environment in environments:
proposal_engines[environment] = SmallMoleculeSetProposalEngine(self._molecules,
system_generators[environment])
# Generate systems
systems = dict()
for environment in environments:
systems[environment] = system_generators[environment].build_system(topologies[environment])
# Define thermodynamic state of interest.
thermodynamic_states = dict()
thermodynamic_states['explicit'] = states.ThermodynamicState(system=systems['explicit'],
temperature=temperature, pressure=pressure)
thermodynamic_states['vacuum'] = states.ThermodynamicState(system=systems['vacuum'], temperature=temperature)
# Create SAMS samplers
from perses.samplers.samplers import ExpandedEnsembleSampler, SAMSSampler
mcmc_samplers = dict()
exen_samplers = dict()
sams_samplers = dict()
for environment in environments:
storage = NetCDFStorageView(self._storage, envname=environment)
if self._geometry_options:
n_torsion_divisions = self._geometry_options['n_torsion_divsions'][environment]
use_sterics = self._geometry_options['use_sterics'][environment]
else:
n_torsion_divisions = 180
use_sterics = False
geometry_engine = geometry.FFAllAngleGeometryEngine(storage=storage, n_torsion_divisions=n_torsion_divisions, use_sterics=use_sterics)
move = mcmc.LangevinSplittingDynamicsMove(timestep=timestep, splitting="V R O R V",
n_restart_attempts=10)
chemical_state_key = proposal_engines[environment].compute_state_key(topologies[environment])
if environment == 'explicit':
sampler_state = states.SamplerState(positions=positions[environment],
box_vectors=systems[environment].getDefaultPeriodicBoxVectors())
else:
sampler_state = states.SamplerState(positions=positions[environment])
mcmc_samplers[environment] = mcmc.MCMCSampler(thermodynamic_states[environment], sampler_state, move)
exen_samplers[environment] = ExpandedEnsembleSampler(mcmc_samplers[environment], topologies[environment],
chemical_state_key, proposal_engines[environment],
geometry_engine,
options={'nsteps': self._ncmc_switching_times[environment]}, storage=storage, ncmc_write_interval=self._ncmc_switching_times[environment])
exen_samplers[environment].verbose = True
sams_samplers[environment] = SAMSSampler(exen_samplers[environment], storage=storage)
sams_samplers[environment].verbose = True
# Create test MultiTargetDesign sampler.
from perses.samplers.samplers import MultiTargetDesign
target_samplers = {sams_samplers['explicit']: 1.0, sams_samplers['vacuum']: -1.0}
designer = MultiTargetDesign(target_samplers, storage=self._storage)
# Store things.
self.molecules = molecules
self.environments = environments
self.topologies = topologies
self.positions = positions
self.system_generators = system_generators
self.proposal_engines = proposal_engines
self.thermodynamic_states = thermodynamic_states
self.mcmc_samplers = mcmc_samplers
self.exen_samplers = exen_samplers
self.sams_samplers = sams_samplers
self.designer = designer
def __init__(self):
super(abl_src_affinity, self).__init__()
#solvents = ['vacuum', 'explicit'] # TODO: Add 'implicit' once GBSA parameterization for small molecules is working
solvents = ['explicit'] # DEBUG
components = [
'src-imatinib', 'abl-imatinib'
] # TODO: Add 'ATP:kinase' complex to enable resistance design
padding = 9.0 * unit.angstrom
explicit_solvent_model = 'tip3p'
setup_path = 'data/abl-src'
thermodynamic_states = dict()
temperature = 300 * unit.kelvin
pressure = 1.0 * unit.atmospheres
# Construct list of all environments
environments = list()
for solvent in solvents:
for component in components:
environment = solvent + '-' + component
environments.append(environment)
# Read SMILES from CSV file of clinical kinase inhibitors.
from pkg_resources import resource_filename
smiles_filename = resource_filename(
'perses', 'data/clinical-kinase-inhibitors.csv')
import csv
molecules = list()
with open(smiles_filename, 'r') as csvfile:
csvreader = csv.reader(csvfile, delimiter=',', quotechar='"')
for row in csvreader:
name = row[0]
smiles = row[1]
molecules.append(smiles)
# Add current molecule
molecules.append(
'Cc1ccc(cc1Nc2nccc(n2)c3cccnc3)NC(=O)c4ccc(cc4)C[NH+]5CCN(CC5)C')
self.molecules = molecules
# Expand molecules without explicit stereochemistry and make canonical isomeric SMILES.
molecules = sanitizeSMILES(self.molecules)
# Create a system generator for desired forcefields
from perses.rjmc.topology_proposal import SystemGenerator
from pkg_resources import resource_filename
gaff_xml_filename = resource_filename('perses', 'data/gaff.xml')
system_generators = dict()
system_generators['explicit'] = SystemGenerator(
[gaff_xml_filename, 'amber99sbildn.xml', 'tip3p.xml'],
forcefield_kwargs={
'nonbondedMethod': app.CutoffPeriodic,
'nonbondedCutoff': 9.0 * unit.angstrom,
'implicitSolvent': None,
'constraints': None
},
use_antechamber=True)
system_generators['implicit'] = SystemGenerator(
[gaff_xml_filename, 'amber99sbildn.xml', 'amber99_obc.xml'],
forcefield_kwargs={
'nonbondedMethod': app.NoCutoff,
'implicitSolvent': app.OBC2,
'constraints': None
},
use_antechamber=True)
system_generators['vacuum'] = SystemGenerator(
[gaff_xml_filename, 'amber99sbildn.xml'],
forcefield_kwargs={
'nonbondedMethod': app.NoCutoff,
'implicitSolvent': None,
'constraints': None
},
use_antechamber=True)
# Copy system generators for all environments
for solvent in solvents:
for component in components:
environment = solvent + '-' + component
system_generators[environment] = system_generators[solvent]
# Load topologies and positions for all components
from simtk.openmm.app import PDBFile, Modeller
topologies = dict()
positions = dict()
for component in components:
pdb_filename = resource_filename(
'perses', os.path.join(setup_path, '%s.pdb' % component))
print(pdb_filename)
pdbfile = PDBFile(pdb_filename)
topologies[component] = pdbfile.topology
positions[component] = pdbfile.positions
# Construct positions and topologies for all solvent environments
for solvent in solvents:
for component in components:
environment = solvent + '-' + component
if solvent == 'explicit':
# Create MODELLER object.
modeller = app.Modeller(topologies[component],
positions[component])
modeller.addSolvent(
system_generators[solvent].getForceField(),
model='tip3p',
padding=9.0 * unit.angstrom)
topologies[environment] = modeller.getTopology()
positions[environment] = modeller.getPositions()
else:
environment = solvent + '-' + component
topologies[environment] = topologies[component]
positions[environment] = positions[component]
# Set up the proposal engines.
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
proposal_metadata = {}
proposal_engines = dict()
for environment in environments:
proposal_engines[environment] = SmallMoleculeSetProposalEngine(
molecules, system_generators[environment], residue_name='MOL')
# Generate systems
systems = dict()
for environment in environments:
systems[environment] = system_generators[environment].build_system(
topologies[environment])
# Define thermodynamic state of interest.
from perses.samplers.thermodynamics import ThermodynamicState
thermodynamic_states = dict()
temperature = 300 * unit.kelvin
pressure = 1.0 * unit.atmospheres
for component in components:
for solvent in solvents:
environment = solvent + '-' + component
if solvent == 'explicit':
thermodynamic_states[environment] = ThermodynamicState(
system=systems[environment],
temperature=temperature,
pressure=pressure)
else:
thermodynamic_states[environment] = ThermodynamicState(
system=systems[environment], temperature=temperature)
# Create SAMS samplers
from perses.samplers.samplers import SamplerState, MCMCSampler, ExpandedEnsembleSampler, SAMSSampler
mcmc_samplers = dict()
exen_samplers = dict()
sams_samplers = dict()
for solvent in solvents:
for component in components:
environment = solvent + '-' + component
chemical_state_key = proposal_engines[
environment].compute_state_key(topologies[environment])
if solvent == 'explicit':
thermodynamic_state = ThermodynamicState(
system=systems[environment],
temperature=temperature,
pressure=pressure)
sampler_state = SamplerState(
system=systems[environment],
positions=positions[environment],
box_vectors=systems[environment].
getDefaultPeriodicBoxVectors())
else:
thermodynamic_state = ThermodynamicState(
system=systems[environment], temperature=temperature)
sampler_state = SamplerState(
system=systems[environment],
positions=positions[environment])
mcmc_samplers[environment] = MCMCSampler(
thermodynamic_state, sampler_state)
mcmc_samplers[
environment].nsteps = 5 # reduce number of steps for testing
mcmc_samplers[environment].verbose = True
exen_samplers[environment] = ExpandedEnsembleSampler(
mcmc_samplers[environment],
topologies[environment],
chemical_state_key,
proposal_engines[environment],
options={'nsteps': 5})
exen_samplers[environment].verbose = True
sams_samplers[environment] = SAMSSampler(
exen_samplers[environment])
sams_samplers[environment].verbose = True
thermodynamic_states[environment] = thermodynamic_state
# Create test MultiTargetDesign sampler.
# TODO: Replace this with inhibitor:kinase and ATP:kinase ratio
from perses.samplers.samplers import MultiTargetDesign
target_samplers = {
sams_samplers['explicit-src-imatinib']: 1.0,
sams_samplers['explicit-abl-imatinib']: -1.0
}
designer = MultiTargetDesign(target_samplers)
designer.verbose = True
# Store things.
self.molecules = molecules
self.environments = environments
self.topologies = topologies
self.positions = positions
self.system_generators = system_generators
self.systems = systems
self.proposal_engines = proposal_engines
self.thermodynamic_states = thermodynamic_states
self.mcmc_samplers = mcmc_samplers
self.exen_samplers = exen_samplers
self.sams_samplers = sams_samplers
self.designer = designer
# This system must currently be minimized.
minimize(self)
def generate_vacuum_hostguest_proposal(current_mol_name="B2",
proposed_mol_name="MOL"):
"""
Generate a test vacuum topology proposal, current positions, and new positions triplet
from two IUPAC molecule names.
Parameters
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
from openmoltools import forcefield_generators
from openmmtools import testsystems
from perses.utils.openeye import smiles_to_oemol
from perses.utils.data import get_data_filename
host_guest = testsystems.HostGuestVacuum()
unsolv_old_system, old_positions, top_old = host_guest.system, host_guest.positions, host_guest.topology
ligand_topology = [res for res in top_old.residues()]
current_mol = forcefield_generators.generateOEMolFromTopologyResidue(
ligand_topology[1]) # guest is second residue in topology
proposed_mol = smiles_to_oemol('C1CC2(CCC1(CC2)C)C')
initial_smiles = oechem.OEMolToSmiles(current_mol)
final_smiles = oechem.OEMolToSmiles(proposed_mol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(
forcefield_generators.gaffTemplateGenerator)
solvated_system = forcefield.createSystem(top_old, removeCMMotion=False)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator(
[gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'],
forcefield_kwargs={
'removeCMMotion': False,
'nonbondedMethod': app.NoCutoff
})
geometry_engine = geometry.FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles],
system_generator,
residue_name=current_mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system,
top_old,
current_mol=current_mol,
proposed_mol=proposed_mol)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal,
old_positions, beta)
return topology_proposal, old_positions, new_positions
def generate_solvated_hybrid_test_topology(current_mol_name="naphthalene",
proposed_mol_name="benzene",
current_mol_smiles=None,
proposed_mol_smiles=None,
vacuum=False,
render_atom_mapping=False):
"""
This function will generate a topology proposal, old positions, and new positions with a geometry proposal (either vacuum or solvated) given a set of input iupacs or smiles.
The function will (by default) read the iupac names first. If they are set to None, then it will attempt to read a set of current and new smiles.
An atom mapping pdf will be generated if specified.
Arguments
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
current_mol_smiles : str (default None)
current mol smiles
proposed_mol_smiles : str (default None)
proposed mol smiles
vacuum: bool (default False)
whether to render a vacuum or solvated topology_proposal
render_atom_mapping : bool (default False)
whether to render the atom map of the current_mol_name and proposed_mol_name
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
import simtk.openmm.app as app
from openmoltools import forcefield_generators
from openeye import oechem
from openmoltools.openeye import iupac_to_oemol, generate_conformers, smiles_to_oemol
from openmoltools import forcefield_generators
import perses.utils.openeye as openeye
from perses.utils.data import get_data_filename
from perses.rjmc.topology_proposal import TopologyProposal, SystemGenerator, SmallMoleculeSetProposalEngine
import simtk.unit as unit
from perses.rjmc.geometry import FFAllAngleGeometryEngine
if current_mol_name != None and proposed_mol_name != None:
try:
old_oemol, new_oemol = iupac_to_oemol(
current_mol_name), iupac_to_oemol(proposed_mol_name)
old_smiles = oechem.OECreateSmiString(
old_oemol,
oechem.OESMILESFlag_DEFAULT | oechem.OESMILESFlag_Hydrogens)
new_smiles = oechem.OECreateSmiString(
new_oemol,
oechem.OESMILESFlag_DEFAULT | oechem.OESMILESFlag_Hydrogens)
except:
raise Exception(
f"either {current_mol_name} or {proposed_mol_name} is not compatible with 'iupac_to_oemol' function!"
)
elif current_mol_smiles != None and proposed_mol_smiles != None:
try:
old_oemol, new_oemol = smiles_to_oemol(
current_mol_smiles), smiles_to_oemol(proposed_mol_smiles)
old_smiles = oechem.OECreateSmiString(
old_oemol,
oechem.OESMILESFlag_DEFAULT | oechem.OESMILESFlag_Hydrogens)
new_smiles = oechem.OECreateSmiString(
new_oemol,
oechem.OESMILESFlag_DEFAULT | oechem.OESMILESFlag_Hydrogens)
except:
raise Exception(f"the variables are not compatible")
else:
raise Exception(
f"either current_mol_name and proposed_mol_name must be specified as iupacs OR current_mol_smiles and proposed_mol_smiles must be specified as smiles strings."
)
old_oemol, old_system, old_positions, old_topology = openeye.createSystemFromSMILES(
old_smiles, title="MOL")
#correct the old positions
old_positions = openeye.extractPositionsFromOEMol(old_oemol)
old_positions = old_positions.in_units_of(unit.nanometers)
new_oemol, new_system, new_positions, new_topology = openeye.createSystemFromSMILES(
new_smiles, title="NEW")
ffxml = forcefield_generators.generateForceFieldFromMolecules(
[old_oemol, new_oemol])
old_oemol.SetTitle('MOL')
new_oemol.SetTitle('MOL')
old_topology = forcefield_generators.generateTopologyFromOEMol(old_oemol)
new_topology = forcefield_generators.generateTopologyFromOEMol(new_oemol)
if not vacuum:
nonbonded_method = app.PME
barostat = openmm.MonteCarloBarostat(1.0 * unit.atmosphere,
300.0 * unit.kelvin, 50)
else:
nonbonded_method = app.NoCutoff
barostat = None
gaff_xml_filename = get_data_filename("data/gaff.xml")
system_generator = SystemGenerator(
[gaff_xml_filename, 'amber99sbildn.xml', 'tip3p.xml'],
barostat=barostat,
forcefield_kwargs={
'removeCMMotion': False,
'nonbondedMethod': nonbonded_method,
'constraints': app.HBonds,
'hydrogenMass': 4.0 * unit.amu
})
system_generator._forcefield.loadFile(StringIO(ffxml))
proposal_engine = SmallMoleculeSetProposalEngine([old_smiles, new_smiles],
system_generator,
residue_name='MOL')
geometry_engine = FFAllAngleGeometryEngine(metadata=None,
use_sterics=False,
n_bond_divisions=1000,
n_angle_divisions=180,
n_torsion_divisions=360,
verbose=True,
storage=None,
bond_softening_constant=1.0,
angle_softening_constant=1.0,
neglect_angles=False)
if not vacuum:
#now to solvate
modeller = app.Modeller(old_topology, old_positions)
hs = [
atom for atom in modeller.topology.atoms()
if atom.element.symbol in ['H']
and atom.residue.name not in ['MOL', 'OLD', 'NEW']
]
modeller.delete(hs)
modeller.addHydrogens(forcefield=system_generator._forcefield)
modeller.addSolvent(system_generator._forcefield,
model='tip3p',
padding=9.0 * unit.angstroms)
solvated_topology = modeller.getTopology()
solvated_positions = modeller.getPositions()
solvated_positions = unit.quantity.Quantity(value=np.array([
list(atom_pos) for atom_pos in
solvated_positions.value_in_unit_system(unit.md_unit_system)
]),
unit=unit.nanometers)
solvated_system = system_generator.build_system(solvated_topology)
#now to create proposal
top_proposal = proposal_engine.propose(
current_system=solvated_system,
current_topology=solvated_topology,
current_mol=old_oemol,
proposed_mol=new_oemol)
new_positions, _ = geometry_engine.propose(top_proposal,
solvated_positions, beta)
if render_atom_mapping:
from perses.utils.smallmolecules import render_atom_mapping
print(
f"new_to_old: {proposal_engine.non_offset_new_to_old_atom_map}"
)
render_atom_mapping(f"{old_smiles}to{new_smiles}.png", old_oemol,
new_oemol,
proposal_engine.non_offset_new_to_old_atom_map)
return top_proposal, solvated_positions, new_positions
else:
vacuum_system = system_generator.build_system(old_topology)
top_proposal = proposal_engine.propose(current_system=vacuum_system,
current_topology=old_topology,
current_mol=old_oemol,
proposed_mol=new_oemol)
new_positions, _ = geometry_engine.propose(top_proposal, old_positions,
beta)
if render_atom_mapping:
from perses.utils.smallmolecules import render_atom_mapping
print(f"new_to_old: {top_proposal._new_to_old_atom_map}")
render_atom_mapping(f"{old_smiles}to{new_smiles}.png", old_oemol,
new_oemol, top_proposal._new_to_old_atom_map)
return top_proposal, old_positions, new_positions
def generate_vacuum_topology_proposal(current_mol_name="benzene", proposed_mol_name="toluene", forcefield_kwargs=None, system_generator_kwargs=None):
"""
Generate a test vacuum topology proposal, current positions, and new positions triplet from two IUPAC molecule names.
Constraints are added to the system by default. To override this, set ``forcefield_kwargs = None``.
Parameters
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
forcefield_kwargs : dict, optional, default=None
Additional arguments to ForceField in addition to
'removeCMMotion': False, 'nonbondedMethod': app.NoCutoff
system_generator_kwargs : dict, optional, default=None
Dict passed onto SystemGenerator
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
gaff_filename = get_data_filename('data/gaff.xml')
default_forcefield_kwargs = {'removeCMMotion': False, 'nonbondedMethod': app.NoCutoff, 'constraints' : app.HBonds}
forcefield_kwargs = default_forcefield_kwargs.update(forcefield_kwargs) if (forcefield_kwargs is not None) else default_forcefield_kwargs
system_generator_kwargs = system_generator_kwargs if (system_generator_kwargs is not None) else dict()
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'],
forcefield_kwargs=forcefield_kwargs,
**system_generator_kwargs)
old_oemol = createOEMolFromIUPAC(current_mol_name)
from openmoltools.forcefield_generators import generateTopologyFromOEMol
old_topology = generateTopologyFromOEMol(old_oemol)
old_positions = extractPositionsFromOEMOL(old_oemol)
old_smiles = oechem.OEMolToSmiles(old_oemol)
old_system = system_generator.build_system(old_topology)
new_oemol = createOEMolFromIUPAC(proposed_mol_name)
new_smiles = oechem.OEMolToSmiles(new_oemol)
geometry_engine = geometry.FFAllAngleGeometryEngine()
proposal_engine = SmallMoleculeSetProposalEngine(
[old_smiles, new_smiles], system_generator, residue_name=current_mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(old_system, old_topology, current_mol=old_oemol, proposed_mol=new_oemol)
# show atom mapping
filename = str(current_mol_name)+str(proposed_mol_name)+'.pdf'
render_atom_mapping(filename, old_oemol, new_oemol, topology_proposal.new_to_old_atom_map)
#generate new positions with geometry engine
new_positions, _ = geometry_engine.propose(topology_proposal, old_positions, beta)
# DEBUG: Zero out bonds and angles for one system
#print('Zeroing bonds of old system')
#for force in topology_proposal.old_system.getForces():
# if force.__class__.__name__ == 'HarmonicAngleForce':
# for index in range(force.getNumAngles()):
# p1, p2, p3, angle, K = force.getAngleParameters(index)
# K *= 0.0
# force.setAngleParameters(index, p1, p2, p3, angle, K)
# if False and force.__class__.__name__ == 'HarmonicBondForce':
# for index in range(force.getNumBonds()):
# p1, p2, r0, K = force.getBondParameters(index)
# K *= 0.0
# force.setBondParameters(index, p1, p2, r0, K)
# DEBUG : Box vectors
#box_vectors = np.eye(3) * 100 * unit.nanometers
#topology_proposal.old_system.setDefaultPeriodicBoxVectors(box_vectors[0,:], box_vectors[1,:], box_vectors[2,:])
#topology_proposal.new_system.setDefaultPeriodicBoxVectors(box_vectors[0,:], box_vectors[1,:], box_vectors[2,:])
return topology_proposal, old_positions, new_positions
def compare_energies(mol_name="naphthalene",
ref_mol_name="benzene",
atom_expression=['Hybridization'],
bond_expression=['Hybridization']):
"""
Make an atom map where the molecule at either lambda endpoint is identical, and check that the energies are also the same.
"""
from openmmtools.constants import kB
from openmmtools import alchemy, states
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
from perses.annihilation.relative import HybridTopologyFactory
from perses.rjmc.geometry import FFAllAngleGeometryEngine
import simtk.openmm as openmm
from perses.utils.openeye import iupac_to_oemol, extractPositionsFromOEMol, generate_conformers
from perses.utils.openeye import generate_expression
from openmmforcefields.generators import SystemGenerator
from openmoltools.forcefield_generators import generateTopologyFromOEMol
from perses.tests.utils import validate_endstate_energies
temperature = 300 * unit.kelvin
# Compute kT and inverse temperature.
kT = kB * temperature
beta = 1.0 / kT
ENERGY_THRESHOLD = 1e-6
atom_expr, bond_expr = generate_expression(
atom_expression), generate_expression(bond_expression)
mol = iupac_to_oemol(mol_name)
mol = generate_conformers(mol, max_confs=1)
refmol = iupac_to_oemol(ref_mol_name)
refmol = generate_conformers(refmol, max_confs=1)
from openforcefield.topology import Molecule
molecules = [Molecule.from_openeye(oemol) for oemol in [refmol, mol]]
barostat = None
forcefield_files = ['amber14/protein.ff14SB.xml', 'amber14/tip3p.xml']
forcefield_kwargs = {
'removeCMMotion': False,
'ewaldErrorTolerance': 1e-4,
'nonbondedMethod': app.NoCutoff,
'constraints': app.HBonds,
'hydrogenMass': 4 * unit.amus
}
system_generator = SystemGenerator(forcefields=forcefield_files,
barostat=barostat,
forcefield_kwargs=forcefield_kwargs,
small_molecule_forcefield='gaff-2.11',
molecules=molecules,
cache=None)
topology = generateTopologyFromOEMol(refmol)
system = system_generator.create_system(topology)
positions = extractPositionsFromOEMol(refmol)
proposal_engine = SmallMoleculeSetProposalEngine([refmol, mol],
system_generator)
proposal = proposal_engine.propose(system,
topology,
atom_expr=atom_expr,
bond_expr=bond_expr)
geometry_engine = FFAllAngleGeometryEngine()
new_positions, _ = geometry_engine.propose(
proposal, positions, beta=beta, validate_energy_bookkeeping=False)
_ = geometry_engine.logp_reverse(proposal, new_positions, positions, beta)
#make a topology proposal with the appropriate data:
factory = HybridTopologyFactory(proposal, positions, new_positions)
if not proposal.unique_new_atoms:
assert geometry_engine.forward_final_context_reduced_potential == None, f"There are no unique new atoms but the geometry_engine's final context reduced potential is not None (i.e. {self._geometry_engine.forward_final_context_reduced_potential})"
assert geometry_engine.forward_atoms_with_positions_reduced_potential == None, f"There are no unique new atoms but the geometry_engine's forward atoms-with-positions-reduced-potential in not None (i.e. { self._geometry_engine.forward_atoms_with_positions_reduced_potential})"
vacuum_added_valence_energy = 0.0
else:
added_valence_energy = geometry_engine.forward_final_context_reduced_potential - geometry_engine.forward_atoms_with_positions_reduced_potential
if not proposal.unique_old_atoms:
assert geometry_engine.reverse_final_context_reduced_potential == None, f"There are no unique old atoms but the geometry_engine's final context reduced potential is not None (i.e. {self._geometry_engine.reverse_final_context_reduced_potential})"
assert geometry_engine.reverse_atoms_with_positions_reduced_potential == None, f"There are no unique old atoms but the geometry_engine's atoms-with-positions-reduced-potential in not None (i.e. { self._geometry_engine.reverse_atoms_with_positions_reduced_potential})"
subtracted_valence_energy = 0.0
else:
subtracted_valence_energy = geometry_engine.reverse_final_context_reduced_potential - geometry_engine.reverse_atoms_with_positions_reduced_potential
zero_state_error, one_state_error = validate_endstate_energies(
factory._topology_proposal,
factory,
added_valence_energy,
subtracted_valence_energy,
beta=1.0 / (kB * temperature),
ENERGY_THRESHOLD=ENERGY_THRESHOLD,
platform=openmm.Platform.getPlatformByName('Reference'))
return factory
def test_logp_forward_check_for_vacuum_topology_proposal(current_mol_name = 'propane', proposed_mol_name = 'octane', num_iterations = 100, neglect_angles = True):
"""
Generate a test vacuum topology proposal, current positions, and new positions triplet
from two IUPAC molecule names. Assert that the logp_forward < 1e3.
This assertion will fail if the proposal order tool proposed the placement of the a carbon before a previously defined carbon in the alkane.
Parameters
----------
current_mol_name : str, optional
name of the first molecule
proposed_mol_name : str, optional
name of the second molecule
Returns
-------
topology_proposal : perses.rjmc.topology_proposal
The topology proposal representing the transformation
current_positions : np.array, unit-bearing
The positions of the initial system
new_positions : np.array, unit-bearing
The positions of the new system
"""
from openmoltools import forcefield_generators
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC, get_data_filename
current_mol, unsolv_old_system, pos_old, top_old = createSystemFromIUPAC(current_mol_name)
proposed_mol = createOEMolFromIUPAC(proposed_mol_name)
initial_smiles = oechem.OEMolToSmiles(current_mol)
final_smiles = oechem.OEMolToSmiles(proposed_mol)
gaff_xml_filename = get_data_filename("data/gaff.xml")
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
solvated_system = forcefield.createSystem(top_old, removeCMMotion=False)
gaff_filename = get_data_filename('data/gaff.xml')
system_generator = SystemGenerator([gaff_filename, 'amber99sbildn.xml', 'tip3p.xml'], forcefield_kwargs={'removeCMMotion': False, 'nonbondedMethod': app.NoCutoff})
geometry_engine = geometry.FFAllAngleGeometryEngine(n_bond_divisions=100, n_angle_divisions=180, n_torsion_divisions=360, neglect_angles = neglect_angles)
proposal_engine = SmallMoleculeSetProposalEngine(
[initial_smiles, final_smiles], system_generator, residue_name=current_mol_name)
#generate topology proposal
topology_proposal = proposal_engine.propose(solvated_system, top_old, current_mol=current_mol, proposed_mol=proposed_mol)
# show atom mapping
filename = str(current_mol_name)+str(proposed_mol_name)+'.pdf'
render_atom_mapping(filename,current_mol,proposed_mol,topology_proposal.new_to_old_atom_map)
total_works = []
for _ in range(num_iterations):
#generate new positions with geometry engine
new_positions, logp_forward = geometry_engine.propose(topology_proposal, pos_old, beta)
logp_reverse = geometry_engine.logp_reverse(topology_proposal, new_positions, pos_old, beta)
#now just render forward and backward work
work_fwd = logp_forward + geometry_engine.forward_final_context_reduced_potential - geometry_engine.forward_atoms_with_positions_reduced_potential
work_bkwd = logp_reverse + geometry_engine.reverse_atoms_with_positions_reduced_potential - geometry_engine.reverse_final_context_reduced_potential
total_work = logp_forward - logp_reverse + geometry_engine.forward_final_context_reduced_potential - geometry_engine.reverse_final_context_reduced_potential
total_works.append(total_work)
print("forward, backward works : {}, {}".format(work_fwd, work_bkwd))
print("total_work: {}".format(total_work))
assert abs(work_fwd - work_bkwd - total_work) < 1, "The difference of fwd and backward works is not equal to the total work (within 1kT)"
assert logp_forward < 1e3, "A heavy atom was proposed in an improper order"
topology = topology.to_openmm()
topology.setPeriodicBoxVectors(system.getDefaultPeriodicBoxVectors())
ifs = oechem.oemolistream()
ifs.open(ligand_filename)
# get the list of molecules
mol_list = [oechem.OEMol(mol) for mol in ifs.GetOEMols()]
for idx, mol in enumerate(mol_list):
mol.SetTitle("MOL{}".format(idx))
oechem.OETriposAtomNames(mol)
initial_mol = mol_list[initial_ligand]
proposal_mol = mol_list[proposal_ligand]
proposal_smiles = SmallMoleculeSetProposalEngine.canonicalize_smiles(oechem.OECreateCanSmiString(proposal_mol))
current_smiles = SmallMoleculeSetProposalEngine.canonicalize_smiles(oechem.OECreateCanSmiString(initial_mol))
barostat = openmm.MonteCarloBarostat(1.0*unit.atmosphere, temperature, 50)
system_generator = SystemGenerator(['amber14/protein.ff14SB.xml', 'gaff.xml', 'amber14/tip3p.xml', 'MCL1_ligands.xml'], barostat=barostat, forcefield_kwargs={'nonbondedMethod': app.PME,
'constraints': app.HBonds,
'hydrogenMass': 4 * unit.amus}, use_antechamber=False)
atom_mapper_filename = os.path.join(setup_directory, "{}_atom_mapper.json".format(project_prefix))
with open(atom_mapper_filename, 'r') as infile:
atom_mapper = SmallMoleculeAtomMapper.from_json(infile.read())
proposal_engine = PremappedSmallMoleculeSetProposalEngine(atom_mapper, system_generator)
topology_proposal = proposal_engine.propose(system, topology, current_smiles=current_smiles, proposed_mol=proposal_mol, map_index=map_index)
def __init__(self, molecules: List[str], output_filename: str, ncmc_switching_times: Dict[str, int], equilibrium_steps: Dict[str, int], timestep: unit.Quantity, initial_molecule: str=None, geometry_options: Dict=None):
self._molecules = [SmallMoleculeSetProposalEngine.canonicalize_smiles(molecule) for molecule in molecules]
environments = ['explicit', 'vacuum']
temperature = 298.15 * unit.kelvin
pressure = 1.0 * unit.atmospheres
constraints = app.HBonds
self._storage = NetCDFStorage(output_filename)
self._ncmc_switching_times = ncmc_switching_times
self._n_equilibrium_steps = equilibrium_steps
self._geometry_options = geometry_options
# Create a system generator for our desired forcefields.
from perses.rjmc.topology_proposal import SystemGenerator
system_generators = dict()
from pkg_resources import resource_filename
gaff_xml_filename = resource_filename('perses', 'data/gaff.xml')
barostat = openmm.MonteCarloBarostat(pressure, temperature)
system_generators['explicit'] = SystemGenerator([gaff_xml_filename, 'tip3p.xml'],
forcefield_kwargs={'nonbondedCutoff': 9.0 * unit.angstrom,
'implicitSolvent': None,
'constraints': constraints,
'ewaldErrorTolerance': 1e-5,
'hydrogenMass': 3.0*unit.amu}, periodic_forcefield_kwargs = {'nonbondedMethod': app.PME}
barostat=barostat)
system_generators['vacuum'] = SystemGenerator([gaff_xml_filename],
forcefield_kwargs={'implicitSolvent': None,
'constraints': constraints,
'hydrogenMass': 3.0*unit.amu}, nonperiodic_forcefield_kwargs = {'nonbondedMethod': app.NoCutoff})
#
# Create topologies and positions
#
topologies = dict()
positions = dict()
from openmoltools import forcefield_generators
forcefield = app.ForceField(gaff_xml_filename, 'tip3p.xml')
forcefield.registerTemplateGenerator(forcefield_generators.gaffTemplateGenerator)
# Create molecule in vacuum.
from perses.utils.openeye import extractPositionsFromOEMol
from openmoltools.openeye import smiles_to_oemol, generate_conformers
if initial_molecule:
smiles = initial_molecule
else:
smiles = np.random.choice(molecules)
molecule = smiles_to_oemol(smiles)
molecule = generate_conformers(molecule, max_confs=1)
topologies['vacuum'] = forcefield_generators.generateTopologyFromOEMol(molecule)
positions['vacuum'] = extractPositionsFromOEMol(molecule)
# Create molecule in solvent.
modeller = app.Modeller(topologies['vacuum'], positions['vacuum'])
modeller.addSolvent(forcefield, model='tip3p', padding=9.0 * unit.angstrom)
topologies['explicit'] = modeller.getTopology()
positions['explicit'] = modeller.getPositions()
# Set up the proposal engines.
proposal_metadata = {}
proposal_engines = dict()
for environment in environments:
proposal_engines[environment] = SmallMoleculeSetProposalEngine(self._molecules,
system_generators[environment])
# Generate systems
systems = dict()
for environment in environments:
systems[environment] = system_generators[environment].build_system(topologies[environment])
# Define thermodynamic state of interest.
thermodynamic_states = dict()
thermodynamic_states['explicit'] = states.ThermodynamicState(system=systems['explicit'],
temperature=temperature, pressure=pressure)
thermodynamic_states['vacuum'] = states.ThermodynamicState(system=systems['vacuum'], temperature=temperature)
# Create SAMS samplers
from perses.samplers.samplers import ExpandedEnsembleSampler, SAMSSampler
mcmc_samplers = dict()
exen_samplers = dict()
sams_samplers = dict()
for environment in environments:
storage = NetCDFStorageView(self._storage, envname=environment)
if self._geometry_options:
n_torsion_divisions = self._geometry_options['n_torsion_divsions'][environment]
use_sterics = self._geometry_options['use_sterics'][environment]
else:
n_torsion_divisions = 180
use_sterics = False
geometry_engine = geometry.FFAllAngleGeometryEngine(storage=storage, n_torsion_divisions=n_torsion_divisions, use_sterics=use_sterics)
move = mcmc.LangevinSplittingDynamicsMove(timestep=timestep, splitting="V R O R V",
n_restart_attempts=10)
chemical_state_key = proposal_engines[environment].compute_state_key(topologies[environment])
if environment == 'explicit':
sampler_state = states.SamplerState(positions=positions[environment],
box_vectors=systems[environment].getDefaultPeriodicBoxVectors())
else:
sampler_state = states.SamplerState(positions=positions[environment])
mcmc_samplers[environment] = mcmc.MCMCSampler(thermodynamic_states[environment], sampler_state, move)
exen_samplers[environment] = ExpandedEnsembleSampler(mcmc_samplers[environment], topologies[environment],
chemical_state_key, proposal_engines[environment],
geometry_engine,
options={'nsteps': self._ncmc_switching_times[environment]}, storage=storage, ncmc_write_interval=self._ncmc_switching_times[environment])
exen_samplers[environment].verbose = True
sams_samplers[environment] = SAMSSampler(exen_samplers[environment], storage=storage)
sams_samplers[environment].verbose = True
# Create test MultiTargetDesign sampler.
from perses.samplers.samplers import MultiTargetDesign
target_samplers = {sams_samplers['explicit']: 1.0, sams_samplers['vacuum']: -1.0}
designer = MultiTargetDesign(target_samplers, storage=self._storage)
# Store things.
self.molecules = molecules
self.environments = environments
self.topologies = topologies
self.positions = positions
self.system_generators = system_generators
self.proposal_engines = proposal_engines
self.thermodynamic_states = thermodynamic_states
self.mcmc_samplers = mcmc_samplers
self.exen_samplers = exen_samplers
self.sams_samplers = sams_samplers
self.designer = designer
topologies[environment] = modeller.getTopology()
positions[environment] = modeller.getPositions()
else:
environment = solvent + '-' + component
topologies[environment] = topologies[component]
positions[environment] = positions[component]
# Set up the proposal engines.
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine
proposal_metadata = { }
proposal_engines = dict()
for environment in environments:
storage = None
if self.storage:
storage = NetCDFStorageView(self.storage, envname=environment)
proposal_engines[environment] = SmallMoleculeSetProposalEngine(molecules, system_generators[environment], residue_name='MOL', storage=storage)
# Generate systems
systems = dict()
for environment in environments:
systems[environment] = system_generators[environment].build_system(topologies[environment])
# Define thermodynamic state of interest.
from perses.samplers.thermodynamics import ThermodynamicState
thermodynamic_states = dict()
temperature = 300*unit.kelvin
pressure = 1.0*unit.atmospheres
for component in components:
for solvent in solvents:
environment = solvent + '-' + component
if solvent == 'explicit':
topology = topology.to_openmm()
topology.setPeriodicBoxVectors(system.getDefaultPeriodicBoxVectors())
ifs = oechem.oemolistream()
ifs.open(ligand_filename)
# get the list of molecules
mol_list = [oechem.OEMol(mol) for mol in ifs.GetOEMols()]
for idx, mol in enumerate(mol_list):
mol.SetTitle("MOL{}".format(idx))
oechem.OETriposAtomNames(mol)
initial_mol = mol_list[initial_ligand]
proposal_mol = mol_list[proposal_ligand]
proposal_smiles = SmallMoleculeSetProposalEngine.canonicalize_smiles(
oechem.OECreateCanSmiString(proposal_mol))
current_smiles = SmallMoleculeSetProposalEngine.canonicalize_smiles(
oechem.OECreateCanSmiString(initial_mol))
barostat = openmm.MonteCarloBarostat(1.0 * unit.atmosphere, temperature,
50)
system_generator = SystemGenerator(
[
'amber14/protein.ff14SB.xml', 'gaff.xml', 'amber14/tip3p.xml',
'MCL1_ligands.xml'
],
barostat=barostat,
forcefield_kwargs={
'nonbondedMethod': app.PME,
'constraints': app.HBonds,
def compare_energies(mol_name="naphthalene", ref_mol_name="benzene"):
"""
Make an atom map where the molecule at either lambda endpoint is identical, and check that the energies are also the same.
"""
from perses.rjmc.topology_proposal import SmallMoleculeSetProposalEngine, TopologyProposal
from perses.annihilation.new_relative import HybridTopologyFactory
import simtk.openmm as openmm
from perses.tests.utils import createOEMolFromIUPAC, createSystemFromIUPAC
mol_name = "naphthalene"
ref_mol_name = "benzene"
mol = createOEMolFromIUPAC(mol_name)
m, system, positions, topology = createSystemFromIUPAC(mol_name)
refmol = createOEMolFromIUPAC(ref_mol_name)
#map one of the rings
atom_map = SmallMoleculeSetProposalEngine._get_mol_atom_map(mol, refmol)
#now use the mapped atoms to generate a new and old system with identical atoms mapped. This will result in the
#same molecule with the same positions for lambda=0 and 1, and ensures a contiguous atom map
effective_atom_map = {value : value for value in atom_map.values()}
#make a topology proposal with the appropriate data:
top_proposal = TopologyProposal(new_topology=topology, new_system=system, old_topology=topology, old_system=system, new_to_old_atom_map=effective_atom_map, new_chemical_state_key="n1", old_chemical_state_key='n2')
factory = HybridTopologyFactory(top_proposal, positions, positions)
alchemical_system = factory.hybrid_system
alchemical_positions = factory.hybrid_positions
integrator = openmm.VerletIntegrator(1)
platform = openmm.Platform.getPlatformByName("Reference")
context = openmm.Context(alchemical_system, integrator, platform)
context.setPositions(alchemical_positions)
functions = {
'lambda_sterics' : '2*lambda * step(0.5 - lambda) + (1.0 - step(0.5 - lambda))',
'lambda_electrostatics' : '2*(lambda - 0.5) * step(lambda - 0.5)',
'lambda_bonds' : 'lambda',
'lambda_angles' : 'lambda',
'lambda_torsions' : 'lambda'
}
#set all to zero
for parm in functions.keys():
context.setParameter(parm, 0.0)
initial_energy = context.getState(getEnergy=True).getPotentialEnergy()
#set all to one
for parm in functions.keys():
context.setParameter(parm, 1.0)
final_energy = context.getState(getEnergy=True).getPotentialEnergy()
if np.abs(final_energy - initial_energy) > 1.0e-6*unit.kilojoule_per_mole:
raise Exception("The energy at the endpoints was not equal for molecule %s" % mol_name)
