def test_replace_reaction_field():
"""Check that replacing reaction-field electrostatics with Custom*Force
yields minimal force differences with original system.
Note that we cannot test for energy consistency or energy overlap because
which atoms are within the cutoff will cause energy difference to vary wildly.
"""
test_cases = [
testsystems.AlanineDipeptideExplicit(
nonbondedMethod=openmm.app.CutoffPeriodic),
testsystems.HostGuestExplicit(
nonbondedMethod=openmm.app.CutoffPeriodic)
]
platform = openmm.Platform.getPlatformByName('Reference')
for test_system in test_cases:
test_name = test_system.__class__.__name__
# Replace reaction field.
modified_rf_system = replace_reaction_field(test_system.system,
switch_width=None)
# Make sure positions are not at minimum.
positions = generate_new_positions(test_system.system,
test_system.positions)
# Test forces.
f = partial(compare_system_forces,
test_system.system,
modified_rf_system,
positions,
name=test_name,
platform=platform)
f.description = "Testing replace_reaction_field on system {}".format(
test_name)
yield f
for test_system in test_cases:
test_name = test_system.__class__.__name__
# Replace reaction field.
modified_rf_system = replace_reaction_field(test_system.system,
switch_width=None,
shifted=True)
# Make sure positions are not at minimum.
positions = generate_new_positions(test_system.system,
test_system.positions)
# Test forces.
f = partial(compare_system_forces,
test_system.system,
modified_rf_system,
positions,
name=test_name,
platform=platform)
f.description = "Testing replace_reaction_field on system {} with shifted=True".format(
test_name)
yield f
def setup_class(cls):
"""Shared test cases for the suite."""
temperature = 300 * unit.kelvin
# Default protocols for tests.
cls.protocol = dict(lambda_electrostatics=[1.0, 0.5, 0.0, 0.0, 0.0],
lambda_sterics=[1.0, 1.0, 1.0, 0.5, 0.0])
cls.restrained_protocol = dict(
lambda_electrostatics=[1.0, 1.0, 0.0, 0.0],
lambda_sterics=[1.0, 1.0, 1.0, 0.0],
lambda_restraints=[0.0, 1.0, 1.0, 1.0])
# Ligand-receptor in implicit solvent.
test_system = testsystems.HostGuestImplicit()
thermodynamic_state = states.ThermodynamicState(
test_system.system, temperature=temperature)
sampler_state = states.SamplerState(
positions=test_system.positions,
box_vectors=test_system.system.getDefaultPeriodicBoxVectors())
topography = Topography(test_system.topology,
ligand_atoms='resname B2')
cls.host_guest_implicit = ('Host-guest implicit', thermodynamic_state,
sampler_state, topography)
# Ligand-receptor in explicit solvent.
test_system = testsystems.HostGuestExplicit()
thermodynamic_state = states.ThermodynamicState(
test_system.system, temperature=temperature)
positions = test_system.positions
box_vectors = test_system.system.getDefaultPeriodicBoxVectors()
sampler_state = states.SamplerState(positions=positions,
box_vectors=box_vectors)
topography = Topography(test_system.topology,
ligand_atoms='resname B2')
cls.host_guest_explicit = ('Host-guest explicit', thermodynamic_state,
sampler_state, topography)
# Peptide solvated in explicit solvent.
test_system = testsystems.AlanineDipeptideExplicit()
thermodynamic_state = states.ThermodynamicState(
test_system.system, temperature=temperature)
positions = test_system.positions
box_vectors = test_system.system.getDefaultPeriodicBoxVectors()
sampler_state = states.SamplerState(positions=positions,
box_vectors=box_vectors)
topography = Topography(test_system.topology)
cls.alanine_explicit = ('Alanine dipeptide explicit',
thermodynamic_state, sampler_state, topography)
# All test cases
cls.all_test_cases = [
cls.host_guest_implicit, cls.host_guest_explicit,
cls.alanine_explicit
]
def test_get_traj():
nc_filename = tempfile.mkdtemp() + "/out.nc"
T_min = 300.0 * unit.kelvin
T_i = [T_min, T_min * 1.01, T_min * 1.1]
n_replicas = len(T_i)
ho = testsystems.AlanineDipeptideExplicit()
system = ho.system
positions = ho.positions
states = [
ThermodynamicState(system=system, temperature=T_i[i])
for i in range(n_replicas)
]
coordinates = [positions] * n_replicas
mpicomm = dummympi.DummyMPIComm()
parameters = {"number_of_iterations": 3}
replica_exchange = ReplicaExchange.create(states,
coordinates,
nc_filename,
mpicomm=mpicomm,
parameters=parameters)
replica_exchange.run()
db = replica_exchange.database
prmtop_filename = testsystems.get_data_filename(
"data/alanine-dipeptide-explicit/alanine-dipeptide.prmtop")
crd_filename = testsystems.get_data_filename(
"data/alanine-dipeptide-explicit/alanine-dipeptide.crd")
trj0 = md.load_restrt(crd_filename, top=prmtop_filename)
db.set_traj(trj0)
trj1 = db.get_traj(state_index=0)
trj2 = db.get_traj(replica_index=0)
def load(sysname):
cutoff = 0.9 * u.nanometers
temperature = 300. * u.kelvin
langevin_timestep = 0.5 * u.femtoseconds
timestep = 2 * u.femtoseconds
equil_steps = 40000
groups = [(0, 1)]
steps_per_hmc = 25
if sysname == "chargedljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
charge=0.15 * u.elementary_charge)
if sysname == "chargedswitchedljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
charge=0.15 * u.elementary_charge,
switch_width=0.34 * u.nanometers)
if sysname == "chargedlongljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
cutoff=1.333 * u.nanometers, charge=0.15 * u.elementary_charge)
if sysname == "chargedswitchedlongljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
cutoff=1.333 * u.nanometers,
charge=0.15 * u.elementary_charge,
switch_width=0.34 * u.nanometers)
if sysname == "chargedswitchedaccuratelongljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
cutoff=1.333 * u.nanometers,
charge=0.15 * u.elementary_charge,
switch_width=0.34 * u.nanometers,
ewaldErrorTolerance=5E-5)
if sysname == "chargedswitchedaccurateljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
charge=0.15 * u.elementary_charge,
switch_width=0.34 * u.nanometers,
ewaldErrorTolerance=5E-5)
if sysname == "ljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj()
if sysname == "longljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
cutoff=1.333 * u.nanometers)
if sysname == "shortljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
cutoff=0.90 * u.nanometers)
if sysname == "shiftedljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
shift=True)
if sysname == "switchedljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
switch_width=0.34 * u.nanometers)
if sysname == "switchedshortljbox":
testsystem, system, positions, timestep, langevin_timestep = load_lj(
cutoff=0.90 * u.nanometers, switch_width=0.34 * u.nanometers)
if sysname == "cluster":
testsystem = testsystems.LennardJonesCluster(nx=8, ny=8, nz=8)
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system, nonbonded=0)
groups = [(0, 1)]
temperature = 25. * u.kelvin
timestep = 40 * u.femtoseconds
if sysname == "shortbigcluster":
testsystem = testsystems.LennardJonesCluster(nx=20,
ny=20,
nz=20,
cutoff=0.75 *
u.nanometers)
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system, nonbonded=0)
groups = [(0, 1)]
temperature = 25. * u.kelvin
timestep = 10 * u.femtoseconds
if sysname == "switchedshortbigcluster":
testsystem = testsystems.LennardJonesCluster(
nx=20,
ny=20,
nz=20,
cutoff=0.75 * u.nanometers,
switch_width=0.1 * u.nanometers)
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system, nonbonded=0)
groups = [(0, 1)]
temperature = 25. * u.kelvin
timestep = 10 * u.femtoseconds
if sysname == "bigcluster":
testsystem = testsystems.LennardJonesCluster(nx=20,
ny=20,
nz=20,
cutoff=1.25 *
u.nanometers)
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system, nonbonded=0)
groups = [(0, 1)]
temperature = 25. * u.kelvin
timestep = 10 * u.femtoseconds
if sysname == "shortcluster":
testsystem = testsystems.LennardJonesCluster(nx=8,
ny=8,
nz=8,
cutoff=0.75 *
u.nanometers)
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system, nonbonded=0)
groups = [(0, 1)]
temperature = 25. * u.kelvin
timestep = 40 * u.femtoseconds
if sysname == "shortwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=0.9 * u.nanometers,
switch_width=None) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "shortswitchedwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=0.9 * u.nanometers,
switch_width=3.0 * u.angstroms) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "water":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
switch_width=None) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "switchedwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
switch_width=3.0 * u.angstroms) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "switchedaccuratewater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
switch_width=3.0 * u.angstroms,
ewaldErrorTolerance=5E-5) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(
system, nonbonded=0, fft=1, others=0) # We may want to try reduce
if sysname == "switchedaccurateflexiblewater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
switch_width=3.0 * u.angstroms,
ewaldErrorTolerance=5E-5,
constrained=False) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
# Using these groups for hyperopt-optimal RESPA integrators
#hmc_integrators.guess_force_groups(system, nonbonded=0, others=1, fft=0)
hmc_integrators.guess_force_groups(system,
nonbonded=1,
others=1,
fft=0)
equil_steps = 100000
langevin_timestep = 0.25 * u.femtoseconds
if sysname == "switchedaccuratebigflexiblewater":
testsystem = testsystems.WaterBox(
box_edge=10.0 * u.nanometers,
cutoff=1.1 * u.nanometers,
switch_width=3.0 * u.angstroms,
ewaldErrorTolerance=5E-5,
constrained=False) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
# Using these groups for hyperopt-optimal RESPA integrators
hmc_integrators.guess_force_groups(system,
nonbonded=1,
others=0,
fft=1)
equil_steps = 100000
langevin_timestep = 0.1 * u.femtoseconds
if sysname == "switchedaccuratestiffflexiblewater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
switch_width=3.0 * u.angstroms,
ewaldErrorTolerance=5E-5,
constrained=False) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
# Using these groups for hyperopt-optimal RESPA integrators
#hmc_integrators.guess_force_groups(system, nonbonded=0, others=1, fft=0)
hmc_integrators.guess_force_groups(system,
nonbonded=1,
others=1,
fft=0)
equil_steps = 100000
langevin_timestep = 0.25 * u.femtoseconds
FACTOR = 10.0
# Make bonded terms stiffer to highlight RESPA advantage
for force in system.getForces():
if type(force) == mm.HarmonicBondForce:
for i in range(force.getNumBonds()):
(a0, a1, length, strength) = force.getBondParameters(i)
force.setBondParameters(i, a0, a1, length,
strength * FACTOR)
elif type(force) == mm.HarmonicAngleForce:
for i in range(force.getNumAngles()):
(a0, a1, a2, length,
strength) = force.getAngleParameters(i)
force.setAngleParameters(i, a0, a1, a2, length,
strength * FACTOR)
if sysname == "switchedaccuratenptwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
switch_width=3.0 * u.angstroms,
ewaldErrorTolerance=5E-5) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
system.addForce(
mm.MonteCarloBarostat(1.0 * u.atmospheres, temperature, 1))
if sysname == "longswitchedwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.5 * u.nanometers,
switch_width=3.0 * u.angstroms) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "rfwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
nonbondedMethod=app.CutoffPeriodic,
switch_width=None) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "switchedrfwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.1 * u.nanometers,
nonbondedMethod=app.CutoffPeriodic,
switch_width=3.0 * u.angstroms) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "longswitchedrfwater":
testsystem = testsystems.WaterBox(
box_edge=3.18 * u.nanometers,
cutoff=1.5 * u.nanometers,
nonbondedMethod=app.CutoffPeriodic,
switch_width=3.0 * u.angstroms) # Around 1060 molecules of water
system, positions = testsystem.system, testsystem.positions
if sysname == "density":
system, positions = load_lb(hydrogenMass=3.0 * u.amu)
hmc_integrators.guess_force_groups(system,
nonbonded=1,
fft=1,
others=0)
groups = [(0, 4), (1, 1)]
timestep = 2.0 * u.femtoseconds
if sysname == "dhfr":
testsystem = testsystems.DHFRExplicit(nonbondedCutoff=1.1 *
u.nanometers,
nonbondedMethod=app.PME,
switch_width=2.0 * u.angstroms,
ewaldErrorTolerance=5E-5)
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system,
nonbonded=1,
fft=2,
others=0)
groups = [(0, 4), (1, 2), (2, 1)]
timestep = 0.75 * u.femtoseconds
equil_steps = 10000
if sysname == "src":
testsystem = testsystems.SrcExplicit(nonbondedCutoff=1.1 *
u.nanometers,
nonbondedMethod=app.PME,
switch_width=2.0 * u.angstroms,
ewaldErrorTolerance=5E-5)
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system,
nonbonded=1,
fft=1,
others=0)
groups = [(0, 2), (1, 1)]
timestep = 0.25 * u.femtoseconds
equil_steps = 1000
if sysname == "ho":
K = 90.0 * u.kilocalories_per_mole / u.angstroms**2
mass = 39.948 * u.amu
timestep = np.sqrt(mass / K) * 0.4
testsystem = testsystems.HarmonicOscillatorArray()
system, positions = testsystem.system, testsystem.positions
groups = [(0, 1)]
if sysname == "customho":
timestep = 1000.0 * u.femtoseconds
testsystem = testsystems.CustomExternalForcesTestSystem()
system, positions = testsystem.system, testsystem.positions
groups = [(0, 1)]
if sysname == "customsplitho":
timestep = 1000.0 * u.femtoseconds
energy_expressions = ("0.75 * (x^2 + y^2 + z^2)",
"0.25 * (x^2 + y^2 + z^2)")
testsystem = testsystems.CustomExternalForcesTestSystem(
energy_expressions=energy_expressions)
system, positions = testsystem.system, testsystem.positions
groups = [(0, 2), (1, 1)]
if sysname == "alanine":
testsystem = testsystems.AlanineDipeptideImplicit()
system, positions = testsystem.system, testsystem.positions
groups = [(0, 2), (1, 1)]
timestep = 2.0 * u.femtoseconds
hmc_integrators.guess_force_groups(system, nonbonded=1, others=0)
#remove_cmm(system) # Unrolled shouldn't need this
equil_steps = 10000
if sysname == "alanineexplicit":
testsystem = testsystems.AlanineDipeptideExplicit(
cutoff=1.1 * u.nanometers,
switch_width=2 * u.angstrom,
ewaldErrorTolerance=5E-5)
system, positions = testsystem.system, testsystem.positions
#groups = [(0, 2), (1, 1), (2, 1)]
#groups = [(0, 2), (1, 1)]
timestep = 1.0 * u.femtoseconds
#hmc_integrators.guess_force_groups(system, nonbonded=1, others=0, fft=2)
#hmc_integrators.guess_force_groups(system, nonbonded=0, others=0, fft=1)
groups = [(0, 1), (1, 2)]
hmc_integrators.guess_force_groups(system,
nonbonded=0,
others=1,
fft=0)
#remove_cmm(system) # Unrolled doesn't need this
equil_steps = 4000
# guess force groups
if "ljbox" in sysname:
timestep = 25 * u.femtoseconds
temperature = 25. * u.kelvin
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system, nonbonded=0, fft=1)
groups = [(0, 2), (1, 1)]
equil_steps = 10000
steps_per_hmc = 15
if sysname == "amoeba":
testsystem = testsystems.AMOEBAIonBox()
system, positions = testsystem.system, testsystem.positions
hmc_integrators.guess_force_groups(system,
nonbonded=0,
fft=1,
others=0)
return system, positions, groups, temperature, timestep, langevin_timestep, testsystem, equil_steps, steps_per_hmc
#test_systems['TIP3P with PME, no switch, no dispersion correction'] = {
# 'test' : testsystems.WaterBox(dispersion_correction=False, switch=False, nonbondedMethod=app.PME),
# 'ligand_atoms' : range(0,3), 'receptor_atoms' : range(3,6) }
test_systems['alanine dipeptide in vacuum'] = {
'test': testsystems.AlanineDipeptideVacuum(),
'ligand_atoms': range(0, 22),
'receptor_atoms': range(22, 22)
}
test_systems['alanine dipeptide in OBC GBSA'] = {
'test': testsystems.AlanineDipeptideImplicit(),
'ligand_atoms': range(0, 22),
'receptor_atoms': range(22, 22)
}
test_systems['alanine dipeptide in TIP3P with reaction field'] = {
'test':
testsystems.AlanineDipeptideExplicit(nonbondedMethod=app.CutoffPeriodic),
'ligand_atoms':
range(0, 22),
'receptor_atoms':
range(22, 22)
}
test_systems['T4 lysozyme L99A with p-xylene in OBC GBSA'] = {
'test': testsystems.LysozymeImplicit(),
'ligand_atoms': range(2603, 2621),
'receptor_atoms': range(0, 2603)
}
#test_systems['Src in OBC GBSA'] = {
# 'test' : testsystems.SrcImplicit(),
# 'ligand_atoms' : range(0,21), 'receptor_atoms' : range(21,4091) }
#test_systems['Src in TIP3P with reaction field'] = {
# 'test' : testsystems.SrcExplicit(nonbondedMethod=app.CutoffPeriodic),
def test_compute_standard_state_correction(self):
"""Test standard state correction works correctly in all ensembles."""
toluene = testsystems.TolueneVacuum()
alanine = testsystems.AlanineDipeptideExplicit()
big_radius = 200.0 * unit.nanometers
temperature = 300.0 * unit.kelvin
# Limit the maximum volume to 1nm^3.
distance_unit = unit.nanometers
state_volume = 1.0 * distance_unit**3
box_vectors = np.identity(3) * np.cbrt(
state_volume / distance_unit**3) * distance_unit
alanine.system.setDefaultPeriodicBoxVectors(*box_vectors)
toluene.system.setDefaultPeriodicBoxVectors(*box_vectors)
# Create systems in various ensembles (NVT, NPT and non-periodic).
nvt_state = states.ThermodynamicState(alanine.system, temperature)
npt_state = states.ThermodynamicState(alanine.system, temperature,
1.0 * unit.atmosphere)
nonperiodic_state = states.ThermodynamicState(toluene.system,
temperature)
def assert_equal_ssc(expected_restraint_volume,
restraint,
thermodynamic_state,
square_well=False,
radius_cutoff=None,
energy_cutoff=None,
max_volume=None):
expected_ssc = -math.log(
STANDARD_STATE_VOLUME / expected_restraint_volume)
ssc = restraint.compute_standard_state_correction(
thermodynamic_state, square_well, radius_cutoff, energy_cutoff,
max_volume)
err_msg = '{} computed SSC != expected SSC'.format(
restraint.__class__.__name__)
nose.tools.assert_equal(ssc, expected_ssc, msg=err_msg)
for restraint in self.restraints:
# In NPT ensemble, an exception is thrown if max_volume is not provided.
with nose.tools.assert_raises_regexp(
TypeError, "max_volume must be provided"):
restraint.compute_standard_state_correction(npt_state)
# With non-periodic systems and reweighting to square-well
# potential, a cutoff must be given.
with nose.tools.assert_raises_regexp(TypeError,
"One between radius_cutoff"):
restraint.compute_standard_state_correction(nonperiodic_state,
square_well=True)
# While there are no problems if we don't reweight to a square-well potential.
restraint.compute_standard_state_correction(nonperiodic_state,
square_well=False)
# SSC is limited by max_volume (in NVT and NPT).
assert_equal_ssc(state_volume,
restraint,
nvt_state,
radius_cutoff=big_radius)
assert_equal_ssc(state_volume,
restraint,
npt_state,
radius_cutoff=big_radius,
max_volume='system')
# SSC is not limited by max_volume with non periodic systems.
expected_ssc = -math.log(STANDARD_STATE_VOLUME / state_volume)
ssc = restraint.compute_standard_state_correction(
nonperiodic_state, radius_cutoff=big_radius)
assert expected_ssc < ssc, (restraint, expected_ssc, ssc)
# Check reweighting to square-well potential.
expected_volume = _compute_sphere_volume(big_radius)
assert_equal_ssc(expected_volume,
restraint,
nonperiodic_state,
square_well=True,
radius_cutoff=big_radius)
energy_cutoff = 10 * nonperiodic_state.kT
radius_cutoff = _compute_harmonic_radius(self.spring_constant,
energy_cutoff)
if isinstance(restraint, FlatBottomRestraintForceMixIn):
radius_cutoff += self.well_radius
expected_volume = _compute_sphere_volume(radius_cutoff)
assert_equal_ssc(expected_volume,
restraint,
nonperiodic_state,
square_well=True,
radius_cutoff=radius_cutoff)
max_volume = 3.0 * unit.nanometers**3
assert_equal_ssc(max_volume,
restraint,
nonperiodic_state,
square_well=True,
max_volume=max_volume)
sampler_state = states.SamplerState(positions=test_system.positions, box_vectors=test_system.system.getDefaultPeriodicBoxVectors())
topography = Topography(test_system.topology, ligand_atoms='resname B2')
cls.host_guest_implicit = ('Host-guest implicit', thermodynamic_state, sampler_state, topography)
# Ligand-receptor in explicit solvent.
test_system = testsystems.HostGuestExplicit()
thermodynamic_state = states.ThermodynamicState(test_system.system,
temperature=temperature)
positions = test_system.positions
box_vectors = test_system.system.getDefaultPeriodicBoxVectors()
sampler_state = states.SamplerState(positions=positions, box_vectors=box_vectors)
topography = Topography(test_system.topology, ligand_atoms='resname B2')
cls.host_guest_explicit = ('Host-guest explicit', thermodynamic_state, sampler_state, topography)
# Peptide solvated in explicit solvent.
test_system = testsystems.AlanineDipeptideExplicit()
thermodynamic_state = states.ThermodynamicState(test_system.system,
temperature=temperature)
positions = test_system.positions
box_vectors = test_system.system.getDefaultPeriodicBoxVectors()
sampler_state = states.SamplerState(positions=positions, box_vectors=box_vectors)
topography = Topography(test_system.topology)
cls.alanine_explicit = ('Alanine dipeptide explicit', thermodynamic_state, sampler_state, topography)
# All test cases
cls.all_test_cases = [cls.host_guest_implicit, cls.host_guest_explicit, cls.alanine_explicit]
@staticmethod
@contextlib.contextmanager
def temporary_storage_path():
"""Generate a storage path in a temporary folder and share it.
