def Minimisation_Function(cluster):
cluster.pbc = False
# Perform the local optimisation method on the cluster.
# Parameter sequence: [p, q, a, xi, r0]
Pt_parameters = {'Pt': [10.71, 3.845, 0.27443, 2.6209, 2.77]}
Gupta_parameters = Pt_parameters
cutoff = 1000
calculator = Gupta(Gupta_parameters, cutoff=cutoff, debug=False)
cluster.set_calculator(calculator)
original_cluster = cluster.copy()
dyn = FIRE(cluster, logfile=None)
#startTime = time.time();
converged = False
try:
dyn.run(fmax=0.01, steps=5000)
converged = dyn.converged()
if not converged:
cluster_name = 'issue_cluster.xyz'
errorMessage = 'The optimisation of cluster ' + str(
original_cluster) + ' did not optimise completely.\n'
errorMessage += 'The cluster of issue before optimisation has been saved as: ' + str(
cluster_name)
write(cluster_name, original_cluster)
raise Exception(errorMessage)
except Exception as exception_message:
cluster_name = 'issue_cluster.xyz'
errorMessage = 'The optimisation of cluster ' + str(
original_cluster) + ' did not optimise completely.\n'
errorMessage += 'The cluster of issue before optimisation has been saved as: ' + str(
cluster_name) + '\n'
errorMessage += exception_message
write(cluster_name, original_cluster)
raise Exception(errorMessage)
#endTime = time.time()
return cluster
def Minimisation_Function(cluster):
cluster.pbc = False
# Perform the local optimisation method on the cluster.
# Parameter sequence: [p, q, a, xi, r0]
#Au_parameters = {'Au': [10.229, 4.0360, 0.2061, 1.7900, 2.884]}
r0 = 4.07/(2.0 ** 0.5)
Au_parameters = {'Au': [10.53, 4.30, 0.2197, 1.855, r0]} # Baletto
Gupta_parameters = Au_parameters
cutoff = 1000
calculator = Gupta(Gupta_parameters, cutoff=cutoff, debug=False)
cluster.set_calculator(calculator)
original_cluster = cluster.copy()
dyn = FIRE(cluster,logfile=None)
converged = False
try:
dyn.run(fmax=0.01,steps=5000)
converged = dyn.converged()
if not converged:
cluster_name = 'issue_cluster.xyz'
errorMessage = 'The optimisation of cluster ' + str(original_cluster) + ' did not optimise completely.\n'
errorMessage += 'The cluster of issue before optimisation has been saved as: '+str(cluster_name)
write(cluster_name,original_cluster)
raise Exception(errorMessage)
except Exception as exception_message:
cluster_name = 'issue_cluster.xyz'
errorMessage = 'The optimisation of cluster ' + str(original_cluster) + ' did not optimise completely.\n'
errorMessage += 'The cluster of issue before optimisation has been saved as: '+str(cluster_name)+'\n'
errorMessage += exception_message
write(cluster_name,original_cluster)
raise Exception(errorMessage)
return cluster
def get_elastic_constants(pot_path=None,
calculator=None,
delta=1e-2,
symbol="W"):
"""
return lattice parameter, and cubic elastic constants: C11, C12, 44
using matscipy function
pot_path - path to the potential
symbol : string
Symbol of the element to pass to ase.lattuce.cubic.SimpleCubicFactory
default is "W" for tungsten
"""
unit_cell = bulk(symbol)
if (pot_path is not None) and (calculator is None):
# create lammps calculator with the potential
lammps = LAMMPSlib(lmpcmds=["pair_style eam/fs",
"pair_coeff * * %s W" % pot_path],
atom_types={'W': 1}, keep_alive=True)
calculator = lammps
unit_cell.set_calculator(calculator)
# simple calculation to get the lattice constant and cohesive energy
# alat0 = W.cell[0][1] - W.cell[0][0]
sf = StrainFilter(unit_cell) # or UnitCellFilter(W) -> to minimise wrt pos, cell
opt = FIRE(sf)
opt.run(fmax=1e-4) # max force in eV/A
alat = unit_cell.cell[0][1] - unit_cell.cell[0][0]
# print("a0 relaxation %.4f --> %.4f" % (a0, a))
# e_coh = W.get_potential_energy()
# print("Cohesive energy %.4f" % e_coh)
Cij, Cij_err = fit_elastic_constants(unit_cell,
symmetry="cubic",
delta=delta)
Cij = Cij/GPa # unit conversion to GPa
elasticMatrix3x3 = Cij[:3, :3]
# average of diagonal elements: C11, C22, C33
C11 = elasticMatrix3x3.diagonal().mean()
# make mask to extract non diagonal elements
mask = np.ones((3, 3), dtype=bool)
np.fill_diagonal(mask, False)
# average of all non diagonal elements from 1 to 3
C12 = elasticMatrix3x3[mask].mean()
# average of diagonal elements from 4 till 6: C44, C55, C66,
C44 = Cij[3:, 3:].diagonal().mean()
# A = 2.*C44/(C11 - C12)
if (pot_path is not None) and (calculator is None):
lammps.lmp.close()
return alat, C11, C12, C44
def solve(self):
#Create the initial particle from the defining string/number atoms
self.particle = NanoClass.genParticle(self.definingString, int(self.numberOfAtoms))
self.reCenter()
self.bestEnergy = self.particle.get_potential_energy()
self.bestParticle = deepcopy(self.particle)
# berendsen = NVTBerendsen(self.particle, 2.5 * units.fs, 2000, taut=0.5*100*units.fs)
berendsen = Langevin(self.particle, 5 * units.fs, units.kB * 2000, 0.005)
dyn = FIRE(atoms=self.particle)
MaxwellBoltzmannDistribution(self.particle,2000*units.kB)
CALCULATIONS=100
for i in range(CALCULATIONS):
if i%1==0:
pDone=float(i)/CALCULATIONS
self.setStatusDone(str(math.floor(pDone*100))+"% | "+self.remainingTime(pDone))
self.checkTimeout()
self.setSolution(self.getAnswer())
MaxwellBoltzmannDistribution(self.particle,2000*units.kB)
self.particle.get_potential_energy()
berendsen.run(500)
dyn.run()
self.reCenter()
testEnergy = self.particle.get_potential_energy()
if (testEnergy < self.bestEnergy):
self.bestEnergy = testEnergy
self.bestParticle = deepcopy(self.particle)
elif ((testEnergy + .5) > self.bestEnergy):
self.particle = NanoClass.genParticle(self.definingString, int(self.numberOfAtoms))
MaxwellBoltzmannDistribution(self.particle,2000*units.kB)
self.particle.get_potential_energy()
if (testEnergy < self.bestEnergy):
self.bestEnergy = testEnergy
self.bestParticle = deepcopy(self.particle)
return self.getAnswer()
def adjust_z_axis(self, cluster):
if self.surface == None:
return
'''
surface_constraints = []
for atom in self.surface:
surface_constraints.append(MyConstraint(atom.index,(0,0,1)))
'''
surface_constraints = []
#surface_constraints.append(ExternalForce(0, 0, 10))
all_bonds = []
all_angles = []
all_dihedrals = []
for index_1 in range(len(self.surface)):
for index_2 in range(index_1+1,len(self.surface)):
bonds_distance = get_distance(self.surface[index_1],self.surface[index_2])
bond = [bonds_distance, [index_1,index_2]]
all_bonds.append(bond)
"""
for index_3 in range(index_2+1,len(self.surface)):
angle_indices = [[index_1,index_2,index_3],[index_3,index_1,index_2],[index_2,index_3,index_1]]
for angle_indice in angle_indices:
angle = [self.surface.get_angle(*angle_indice) * pi / 180, angle_indice]
all_angles.append(angle)
'''
for index_4 in range(index_3+1,len(self.surface)):
dihedral_indices = [[index_1,index_2,index_3,index_4],[index_1,index_2,index_3,index_4],[index_1,index_2,index_3,index_4]]
for dihedral_indice in dihedral_indices:
dihedral = [self.surface.get_dihedral(*dihedral_indice) * pi / 180, dihedral_indice]
all_dihedrals.append(dihedral)
'''
"""
surface_constraints.append(FixInternals(bonds=all_bonds, angles=all_angles, dihedrals=all_dihedrals))
#self.surface.set_constraint(surface_constraints)
c = FixAtoms(indices=range(len(self.surface),len(self.surface)+len(cluster)))
cluster_constraints = [c]
#cluster.set_constraint(cluster_constraints)
for atom in self.surface:
atom.z -= 40.0
system = self.surface + cluster
system.set_calculator(EMT())
system.set_constraint(surface_constraints+cluster_constraints)
dyn = FIRE(system)
converged = False
import pdb; pdb.set_trace()
try:
dyn.run(fmax=0.01,steps=5000)
converged = dyn.converged()
if not converged:
import os
name = os.path.basename(os.getcwd())
errorMessage = 'The optimisation of cluster ' + name + ' did not optimise completely.'
print(errorMessage, file=sys.stderr)
print(errorMessage)
except:
print('Local Optimiser Failed for some reason.')
import pdb; pdb.set_trace()
def get_dynamics(atoms, mcfm_pot, T=300):
# ------ Set up logfiles
traj_interval = 10
thermoPrintstatus_log = open("log_thermoPrintstatus.log", "w")
outputTrajectory = open("log_trajectory.xyz", "w")
mcfmError_log = open("log_mcfmError.log", "w")
# ------ Let optimiser use the base potential and relax the per atom energies
mcfm_pot.qm_cluster.flagging_module.ema_parameter = 0.1
mcfm_pot.qm_cluster.flagging_module.qm_flag_potential_energies =\
np.ones((len(atoms), 2), dtype=float) * 1001
# ------ Minimize positions
opt = FIRE(atoms)
optimTrajectory = open("log_optimizationTrajectory.xyz", "w")
opt.attach(trajectory_writer, 1, atoms, optimTrajectory, writeResults=True)
opt.run(fmax=0.05, steps=1000)
# ------ Define ASE dyamics
sim_T = T * units.kB
MaxwellBoltzmannDistribution(atoms, 2 * sim_T)
timestep = 5e-1 * units.fs
friction = 1e-2
dynamics = Langevin(atoms, timestep, sim_T, friction, fixcm=False)
dynamics.attach(mcfm_thermo_printstatus, 100, 100, dynamics,
atoms, mcfm_pot, logfile=thermoPrintstatus_log)
dynamics.attach(trajectory_writer, traj_interval, atoms, outputTrajectory, writeResults=False)
dynamics.attach(mcfm_error_logger, 100, 100, dynamics, atoms, mcfm_pot, logfile=mcfmError_log)
return dynamics
def minimize_energy(atoms, nstep, pressure_interval=10):
bulkmodulus = 140e9 / 1e5 # Bulk modulus of typical metal (Cu), in bar.
dyn = FIRE(atoms)
unstress = Inhomogeneous_NPTBerendsen(atoms, 50*units.fs, 0,
taup=5000*units.fs,
compressibility=1/bulkmodulus)
dyn.attach(unstress.scale_positions_and_cell, interval=10)
dyn.run(steps=nstep)
def solve(self):
self.setStatusDone("Initializing configuration...")
self.particle = NanoClass.genParticle(self.definingString, int(self.numberOfAtoms))
self.reCenter()
self.bestEnergy = self.particle.get_potential_energy()
self.bestParticle = self.particle.copy()
berendsen = Langevin(self.particle, 5*units.fs, units.kB*2000,0.005)
dyn = FIRE(atoms=self.particle)
dyn.run(500)
MaxwellBoltzmannDistribution(self.particle,2000*units.kB)
MAXIMUM_ITERATIONS = 20
ITERATION = 0
BEST_POTENTIAL_ENERGY = 999999
BEST_PARTICLE = None
queue = [( self.particle.get_potential_energy(), self.particle)]
pDone=float(ITERATION)/MAXIMUM_ITERATIONS
self.setStatusDone(str(math.floor(pDone*100))+"% | "+self.remainingTime(pDone))
self.checkTimeout()
current_particle = self.bestParticle.copy()
calc = EMT()
current_particle.set_calculator(calc)
self.setSolution(self.getAnswer(current_particle, current_particle.get_potential_energy()))
while ITERATION < MAXIMUM_ITERATIONS:
new_parent = heappop(queue)[1].copy()
calc = EMT()
new_parent.set_calculator(calc)
#print new_parent.get_positions()
#print new_parent.get_potential_energy()
for x in range(5):
new_child = self.create_child_from(new_parent)
potential_energy = copy.deepcopy(new_child.get_potential_energy())
heappush(queue, (potential_energy, new_child))
if potential_energy < BEST_POTENTIAL_ENERGY:
#print "--------------- NEW BEST FOUND ---------------"
#print "POTENTIAL ENERGY = ", potential_energy
BEST_POTENTIAL_ENERGY = potential_energy
self.bestParticle = new_child
#print new_child.positions
pDone=float(ITERATION)/MAXIMUM_ITERATIONS
self.setStatusDone(str(math.floor(pDone*100))+"% | "+self.remainingTime(pDone))
self.checkTimeout()
self.setSolution(self.getAnswer(self.bestParticle, BEST_POTENTIAL_ENERGY))
ITERATION += 1
return self.getAnswer(self.bestParticle, BEST_POTENTIAL_ENERGY)
def relax(atoms, cellbounds=None):
# Performs a variable-cell relaxation of the structure
calc = EMT()
atoms.set_calculator(calc)
converged = False
niter = 0
while not converged and niter < 10:
if cellbounds is not None:
cell = atoms.get_cell()
if not cellbounds.is_within_bounds(cell):
niggli_reduce(atoms)
cell = atoms.get_cell()
if not cellbounds.is_within_bounds(cell):
# Niggli reduction did not bring the unit cell
# within the specified bounds; this candidate should
# be discarded so we set an absurdly high energy
finalize(atoms, 1e9)
return
ecf = ExpCellFilter(atoms)
dyn = FIRE(ecf, maxmove=0.2, logfile=None, trajectory=None)
dyn.run(fmax=1e-3, steps=100)
converged = dyn.converged()
niter += 1
dyn = FIRE(atoms, maxmove=0.2, logfile=None, trajectory=None)
dyn.run(fmax=1e-2, steps=100)
e = atoms.get_potential_energy()
f = atoms.get_forces()
s = atoms.get_stress()
finalize(atoms, energy=e, forces=f, stress=s)
def _optimize(self):
"""Perform an optimization."""
self._atoms.set_momenta(np.zeros(self._atoms.get_momenta().shape))
geo_opt = FIRE(self._atoms)
geo_opt.run(fmax=5e-02)
ecf = ExpCellFilter(self._atoms)
opt = self._optimizer(ecf,
trajectory='qn%05i.traj' % self._counter,
logfile='qn%05i.log' % self._counter)
self._log('msg', 'Optimization: qn%05i' % self._counter)
opt.run(fmax=self._fmax)
self._log('ene')
def calc_gap():
oraxis = '0,0,1'
pot_param = PotentialParameters()
ener_per_atom = pot_param.gs_ener_per_atom()
selected_grains = GrainBoundary.select().where(
GrainBoundary.orientation_axis == oraxis).where(
GrainBoundary.boundary_plane != oraxis)
f = open('./locenviron/gap_energies.dat', 'a')
for gb in selected_grains.order_by(GrainBoundary.angle)[2:]:
subgbs = (gb.subgrains.select(
GrainBoundary,
SubGrainBoundary).where(SubGrainBoundary.potential ==
'PotBH.xml').join(GrainBoundary).dicts())
subgbs = [
(16.02 * (subgb['E_gb'] -
float(subgb['n_at'] * ener_per_atom['PotBH.xml'])) /
(2.0 * subgb['area']), subgb) for subgb in subgbs
]
subgbs.sort(key=lambda x: x[0])
try:
print subgbs[0][1]['path']
continue
target_dir = os.path.join('./grain_boundaries',
subgbs[0][1]['path'])
struct_file = os.path.join(target_dir,
subgbs[0][1]['gbid']) + '_traj.xyz'
print struct_file
ats = AtomsReader(struct_file)[-1]
pot = Potential('IP GAP', param_filename='gp33b.xml')
ats.set_calculator(pot)
print subgbs[0][1]['n_at'], subgbs[0][1]['area']
strain_mask = [0, 0, 1, 0, 0, 0]
ucf = UnitCellFilter(ats, strain_mask)
opt = FIRE(ucf)
FORCE_TOL = 0.1
opt.run(fmax=FORCE_TOL)
gap_en = ats.get_potential_energy()
print gap_en
print round(gb.angle * (180.0 / 3.14159), 3), round(
subgbs[0][0], 3), 16.02 * (gap_en - float(
subgbs[0][1]['n_at'] * ener_per_atom['gp33b.xml'])) / (
2.0 * subgbs[0][1]['area'])
print >> f, round(gb.angle * (180.0 / 3.14159), 3), round(
subgbs[0][0], 3), 16.02 * (gap_en - float(
subgbs[0][1]['n_at'] * ener_per_atom['gp33b.xml'])) / (
2.0 * subgbs[0][1]['area'])
ats.write('./locenviron/{}.xyz'.format(subgbs[0][1]['gbid']))
except IndexError:
print '\t', round(gb.angle * (180.0 / 3.14159), 3), subgbs
def _calc_quick(atoms, supercell=(1, 1, 1), delta=0.01):
"""Calculates the Hessian for a given atoms object just like :func:`calc`,
*but*, it uses symmetry to speed up the calculation. Depending on the
calculator being used, it is possible that the symmetrized result may be
different from the full result with all displacements, done manually by
:func:`calc`.
Args:
atoms (matdb.atoms.Atoms): atomic structure of the *primitive*.
supercell (list): or `tuple` or :class:`numpy.ndarray` specifying the
integer supercell matrix.
delta (float): displacement in Angstroms of each atom when computing the
phonons.
Returns:
numpy.ndarray: Hessian matrix that has dimension `(natoms*3, natoms*3)`,
where `natoms` is the number of atoms in the *supercell*.
"""
#We need to make sure we are at the zero of the potential before
ratoms = atoms.copy()
try:
with open("phonons.log", 'w') as f:
with redirect_stdout(f):
print(ratoms.get_forces())
minim = FIRE(ratoms)
minim.run(fmax=1e-4, steps=100)
except:
#The potential is unstable probably. Issue a warning.
msg.warn(
"Couldn't optimize the atoms object. Potential may be unstable.")
primitive = matdb_to_phonopy(ratoms)
phonon = Phonopy(primitive, conform_supercell(supercell))
phonon.generate_displacements(distance=delta)
supercells = phonon.get_supercells_with_displacements()
pot = atoms.get_calculator()
assert pot is not None
forces = []
for scell in supercells:
matoms = phonopy_to_matdb(scell)
#Call a manual reset of the calculator so that we explicitly recalculate
#the forces for the current atoms object.
pot.reset()
matoms.set_calculator(pot)
forces.append(matoms.get_forces())
phonon.set_forces(forces)
phonon.produce_force_constants()
return unroll_fc(phonon._force_constants)
def test_fire():
a = bulk('Au')
a *= (2, 2, 2)
a[0].x += 0.5
a.set_calculator(EMT())
opt = FIRE(a, dtmax=1.0, dt=1.0, maxmove=100.0, downhill_check=False)
opt.run(fmax=0.001)
e1 = a.get_potential_energy()
n1 = opt.nsteps
a = bulk('Au')
a *= (2, 2, 2)
a[0].x += 0.5
a.set_calculator(EMT())
reset_history = []
def callback(a, r, e, e_last):
reset_history.append([e - e_last])
opt = FIRE(a, dtmax=1.0, dt=1.0, maxmove=100.0, downhill_check=True,
position_reset_callback=callback)
opt.run(fmax=0.001)
e2 = a.get_potential_energy()
n2 = opt.nsteps
assert abs(e1 - e2) < 1e-6
assert n2 < n1
assert (np.array(reset_history) > 0).all
def test_mirror():
from ase.build import molecule
from ase.constraints import MirrorForce, FixBondLength, MirrorTorque
from ase.constraints import ExternalForce
from ase.optimize import FIRE
from ase.calculators.emt import EMT
atoms = molecule('cyclobutene')
dist = atoms.get_distance(0, 1)
con1 = MirrorForce(2, 3, max_dist=5., fmax=0.05)
con2 = FixBondLength(0, 1)
atoms.set_constraint([con1, con2])
atoms.calc = EMT()
opt = FIRE(atoms)
opt.run(fmax=0.05)
assert round(dist - atoms.get_distance(0, 1), 5) == 0
atoms = molecule('butadiene')
# Break symmetry
atoms[0].position[2] += 0.2
dist = atoms.get_distance(1, 2)
con1 = MirrorTorque(0, 1, 2, 3, fmax=0.05)
con2 = ExternalForce(9, 4, f_ext=0.1)
atoms.set_constraint([con1, con2])
atoms.calc = EMT()
opt = FIRE(atoms)
opt.run(fmax=0.05, steps=300)
def getPath(Reac,Prod,gl):
xyzfile3 = open(("IRC3.xyz"), "w")
Path = []
Path.append(Reac.copy())
for i in range(0,30):
image = Reac.copy()
image = tl.setCalc(image,"DOS/", gl.lowerMethod, gl.lowerLevel)
Path.append(image)
image = Prod.copy()
image = tl.setCalc(image,"DOS/", gl.lowerMethod, gl.lowerLevel)
Path.append(image)
neb1 = NEB(Path,k=1.0,remove_rotation_and_translation = True)
try:
neb1.interpolate('idpp',optimizer="MDMin",k=1.0)
except:
neb1.interpolate()
optimizer = FIRE(neb1)
optimizer.run(fmax=0.07, steps = 500)
neb2 = NEB(Path,k=1.0, climb=True, remove_rotation_and_translation = True )
optimizer = FIRE(neb2)
optimizer.run(fmax=0.07, steps = 1500)
for i in range(0,len(Path)):
tl.printTraj(xyzfile3, Path[i])
xyzfile3.close()
return Path
def test_symmetry_sparse(self):
"""
Test the symmetry of the dense Hessian matrix
"""
atoms = FaceCenteredCubic('H', size=[2,2,2], latticeconstant=2.37126)
calc = Polydisperse(InversePowerLawPotential(1.0, 1.4, 0.1, 3, 1, 2.22))
atoms.set_masses(masses=np.repeat(1.0, len(atoms)))
atoms.set_array("size", np.random.uniform(1.0, 2.22, size=len(atoms)), dtype=float)
atoms.set_calculator(calc)
dyn = FIRE(atoms)
dyn.run(fmax=1e-5)
H = calc.hessian_matrix(atoms)
H = H.todense()
self.assertArrayAlmostEqual(np.sum(np.abs(H-H.T)), 0, tol=1e-5)
def test_combine_mm2(testdir):
# More biased initial positions for faster test. Set
# to false for a slower, harder test.
fast_test = True
atoms = make_4mer()
atoms.constraints = FixBondLengths([(3 * i + j, 3 * i + (j + 1) % 3)
for i in range(int(len(atoms) // 3))
for j in [0, 1, 2]])
atoms.calc = TIP3P(np.Inf)
tag = '4mer_tip3_opt.'
with FIRE(atoms, logfile=tag + 'log', trajectory=tag + 'traj') as opt:
opt.run(fmax=0.05)
tip3_pos = atoms.get_positions()
sig = np.array([sigma0, 0, 0])
eps = np.array([epsilon0, 0, 0])
rc = np.Inf
idxes = [[0, 1, 2], [3, 4, 5], [6, 7, 8], [9, 10, 11],
list(range(6)),
list(range(9)),
list(range(6, 12))]
for ii, idx in enumerate(idxes):
atoms = make_4mer()
if fast_test:
atoms.set_positions(tip3_pos)
atoms.constraints = FixBondLengths([(3 * i + j, 3 * i + (j + 1) % 3)
for i in range(len(atoms) // 3)
for j in [0, 1, 2]])
atoms.calc = CombineMM(idx,
3,
3,
TIP3P(rc),
TIP3P(rc),
sig,
eps,
sig,
eps,
rc=rc)
tag = '4mer_combtip3_opt_{0:02d}.'.format(ii)
with FIRE(atoms, logfile=tag + 'log', trajectory=tag + 'traj') as opt:
opt.run(fmax=0.05)
assert ((abs(atoms.positions - tip3_pos) < 1e-8).all())
print('{0}: {1!s:>28s}: Same Geometry as TIP3P'.format(
atoms.calc.name, idx))
def test_fix_bond_length_mic():
import ase
from ase.calculators.lj import LennardJones
from ase.constraints import FixBondLength
from ase.optimize import FIRE
for wrap in [False, True]:
a = ase.Atoms('CCC',
positions=[[1, 0, 5],
[0, 1, 5],
[-1, 0.5, 5]],
cell=[10, 10, 10],
pbc=True)
if wrap:
a.set_scaled_positions(a.get_scaled_positions() % 1.0)
a.calc = LennardJones()
a.set_constraint(FixBondLength(0, 2))
d1 = a.get_distance(0, 2, mic=True)
FIRE(a, logfile=None).run(fmax=0.01)
e = a.get_potential_energy()
d2 = a.get_distance(0, 2, mic=True)
assert abs(e - -2.034988) < 1e-6
assert abs(d1 - d2) < 1e-6
def test_hessian_random_structure(self):
"""
Test the computation of the Hessian matrix
"""
atoms = FaceCenteredCubic('H', size=[2,2,2], latticeconstant=2.37126)
calc = Polydisperse(InversePowerLawPotential(1.0, 1.4, 0.1, 3, 1, 2.22))
atoms.set_masses(masses=np.repeat(1.0, len(atoms)))
atoms.set_array("size", np.random.uniform(1.0, 2.22, size=len(atoms)), dtype=float)
atoms.set_calculator(calc)
dyn = FIRE(atoms)
dyn.run(fmax=1e-5)
H_analytical = calc.hessian_matrix(atoms)
H_analytical = H_analytical.todense()
H_numerical = fd_hessian(atoms, dx=1e-5, indices=None)
H_numerical = H_numerical.todense()
self.assertArrayAlmostEqual(H_analytical, H_numerical, tol=self.tol)
def test_anisotropic_near_field_solution(self):
"""
Run an atomistic calculation of a harmonic solid and compare to
continuum solution.
"""
if not atomistica:
print('Atomistica not available. Skipping test.')
return
for nx in [ 8, 16, 32, 64 ]:
for calc, a, C11, C12, C44, surface_energy, bulk_coordination in [
#( atomistica.DoubleHarmonic(k1=1.0, r1=1.0, k2=1.0,
# r2=math.sqrt(2), cutoff=1.6),
# clusters.sc('He', 1.0, [nx,nx,1], [1,0,0], [0,1,0]),
# 3, 1, 1, 0.05, 6 ),
( atomistica.Harmonic(k=1.0, r0=1.0, cutoff=1.3, shift=True),
clusters.fcc('He', math.sqrt(2.0), [nx,nx,1], [1,0,0],
[0,1,0]),
math.sqrt(2), 1.0/math.sqrt(2), 1.0/math.sqrt(2), 0.05, 12)
]:
clusters.set_groups(a, (nx, nx, 1), 0.5, 0.5)
crack = CubicCrystalCrack([1,0,0], [0,1,0], C11, C12, C44)
a.center(vacuum=20.0, axis=0)
a.center(vacuum=20.0, axis=1)
a.set_calculator(calc)
sx, sy, sz = a.cell.diagonal()
tip_x = sx/2
tip_y = sy/2
k1g = crack.k1g(surface_energy)
r0 = a.positions.copy()
u, v = crack.displacements(a.positions[:,0], a.positions[:,1],
tip_x, tip_y, k1g)
a.positions[:,0] += u
a.positions[:,1] += v
g = a.get_array('groups')
a.set_constraint(FixAtoms(mask=g==0))
#ase.io.write('initial_{}.xyz'.format(nx), a, format='extxyz')
x1, y1, z1 = a.positions.copy().T
FIRE(a, logfile=None).run(fmax=1e-3)
x2, y2, z2 = a.positions.T
# Get coordination numbers and find properly coordinated atoms
coord = calc.nl.get_coordination_numbers(calc.particles, 1.1)
mask=coord == bulk_coordination
residual = np.sqrt(((x2-x1)/u)**2 + ((y2-y1)/v)**2)
#a.set_array('residual', residual)
#ase.io.write('final_{}.xyz'.format(nx), a, format='extxyz')
#print(np.max(residual[mask]))
self.assertTrue(np.max(residual[mask]) < 0.2)
def Minimisation_Function(cluster, calculator):
cluster.pbc = False
cluster.set_calculator(calculator)
from ase.optimize import FIRE
dyn = FIRE(cluster, logfile=None)
try:
dyn.run(fmax=0.01, steps=5000)
converged = dyn.converged()
if not converged:
errorMessage = 'The optimisation of cluster ' + str(
cluster_name) + ' did not optimise completely.'
print(errorMessage, file=sys.stderr)
print(errorMessage)
except Exception:
print('Local Optimiser Failed for some reason.')
return cluster
def test_rotation(self):
for make_atoms, calc in [
# ( lambda a0,x :
# FaceCenteredCubic('He', size=[1,1,1],
# latticeconstant=3.5 if a0 is None else a0,
# directions=x),
# LJCut(epsilon=10.2, sigma=2.28, cutoff=5.0, shift=True) ),
( lambda a0,x : FaceCenteredCubic('Au', size=[1,1,1],
latticeconstant=a0, directions=x),
EAM('Au-Grochola-JCP05.eam.alloy') ),
# ( lambda a0,x : Diamond('Si', size=[1,1,1], latticeconstant=a0,
# directions=x),
# Kumagai() )
#( lambda a0,x : FaceCenteredCubic('Au', size=[1,1,1],
# latticeconstant=a0, directions=x),
# EAM(potential='Au-Grochola-JCP05.eam.alloy') ),
]:
a = make_atoms(None, [[1,0,0], [0,1,0], [0,0,1]])
a.set_calculator(calc)
FIRE(StrainFilter(a, mask=[1,1,1,0,0,0]), logfile=None) \
.run(fmax=self.fmax)
latticeconstant = np.mean(a.cell.diagonal())
C6 = measure_triclinic_elastic_constants(a, delta=self.delta,
fmax=self.fmax)
C11, C12, C44 = Voigt_6x6_to_cubic(C6)/GPa
el = CubicElasticModuli(C11, C12, C44)
C_m = measure_triclinic_elastic_constants(a, delta=self.delta,
fmax=self.fmax)/GPa
self.assertArrayAlmostEqual(el.stiffness(), C_m, tol=0.01)
for directions in [ [[1,0,0], [0,1,0], [0,0,1]],
[[0,1,0], [0,0,1], [1,0,0]],
[[1,1,0], [0,0,1], [1,-1,0]],
[[1,1,1], [-1,-1,2], [1,-1,0]] ]:
a, b, c = directions
directions = np.array([ np.array(x)/np.linalg.norm(x)
for x in directions ])
a = make_atoms(latticeconstant, directions)
a.set_calculator(calc)
C = el.rotate(directions)
C_check = el._rotate_explicit(directions)
C_check2 = rotate_cubic_elastic_constants(C11, C12, C44,
directions)
C_check3 = \
rotate_elastic_constants(cubic_to_Voigt_6x6(C11, C12, C44),
directions)
self.assertArrayAlmostEqual(C, C_check, tol=1e-6)
self.assertArrayAlmostEqual(C, C_check2, tol=1e-6)
self.assertArrayAlmostEqual(C, C_check3, tol=1e-6)
C_m = measure_triclinic_elastic_constants(a, delta=self.delta,
fmax=self.fmax)/GPa
self.assertArrayAlmostEqual(C, C_m, tol=1e-2)
def optimizeMolecule(molecule,NMoves,creationString):
bestEnergy = 0.
totalMinimaFound = 0
sinceLastFind = 0
calc = QSC()
molecule.set_calculator(calc)
for i in range(NMoves):
molecule = newMove(molecule)
molecule = preventExplosions(molecule)
molecule.center()
sinceLastFind += 1
# do a last optimization of the structure
dyn = FIRE(molecule)
dyn.run(steps = 2000)
newEnergy = molecule.get_potential_energy()
if (newEnergy < bestEnergy):
optimizedMolecule = molecule
bestEnergy = newEnergy
line = str(totalMinimaFound) + " " + str(molecule.get_potential_energy()) + " " + str(i) +"\n"
print line
f = open('EnergyList.txt','a')
f.write(line)
f.close()
minimaList = PickleTrajectory(str(creationString),mode='a')
minimaList.write(optimizedMolecule)
totalMinimaFound += 1
minimaList.close()
sinceLastFind = 0
elif (sinceLastFind < 200):
break
minimaList.close()
minimaList = PickleTrajectory(str(creationString),mode='r')
atomslist = [atom for atom in minimaList]
ase.io.write('movie.xyz',atomslist,format='xyz') # write a movie file of our dynamics
minimaList.close()
return optimizedMolecule
def optimse_Cu(cluster):
Cu_parameters = {'Cu': [10.960, 2.2780, 0.0855, 1.2240, 2.556]}
cluster.set_calculator(Gupta(Cu_parameters, cutoff=1000, debug=True))
dyn = FIRE(cluster)
try:
import time
startTime = time.time()
dyn.run(fmax=0.01, steps=5000)
endTime = time.time()
if not dyn.converged():
import os
name = os.path.basename(os.getcwd())
errorMessage = 'The optimisation of cluster ' + name + ' did not optimise completely.'
print >> sys.stderr, errorMessage
print errorMessage
except:
print('Local Optimiser Failed for some reason.')
def _optimize(self):
"""Perform an optimization."""
# del self._atoms.constraints
self._atoms.set_momenta(np.zeros(self._atoms.get_momenta().shape))
geo_opt = FIRE(self._atoms)
geo_opt.run(fmax=self._fmax2)
ecf = ExpCellFilter(self._atoms)
opt = self._optimizer(ecf,
trajectory='qn%05i.traj' % self._counter,
logfile='qn%05i.log' % self._counter)
self._log('msg', 'Optimization: qn%05i' % self._counter)
opt.run(fmax=self._fmax)
self._log('ene')
# del self._atoms.constraints
tri_mat, coord_transform = convert_cell_4NPT(self._atoms.get_cell())
self._atoms.set_positions([np.matmul(coord_transform, position) for position in self._atoms.get_positions()])
self._atoms.set_cell(tri_mat.transpose())
def solve(self):
#Create the initial particle from the defining string/number atoms
temp = 1750
mintemp = 150
self.particle = genParticle(self.definingString,int(self.numberOfAtoms))
if (len(self.particle) < 16):
temp = 1250
maxtemp = temp
berendsen = Langevin(self.particle, 2.5 * units.fs, units.kB * temp, 0.02)
# the 5.0 * units.fs is used instead of 0.1 * units.fs b/c it makes the program run faster
MaxwellBoltzmannDistribution(self.particle,units.kB * temp)
self.bestEnergy = self.particle.get_potential_energy()
self.bestParticle = deepcopy(self.particle)
self.reCenter()
self.getAnswer()
while (temp > mintemp):
berendsen = Langevin(self.particle, 2.5 * units.fs, units.kB * temp, 0.02)
berendsen.run(100)
testEnergy = self.particle.get_potential_energy()
self.bestEnergy = self.particle.get_potential_energy()
self.bestParticle = deepcopy(self.particle)
self.reCenter()
self.getAnswer()
temp -= 10
if (temp % 50 == 0):
self.bestEnergy = self.particle.get_potential_energy()
self.bestParticle = deepcopy(self.particle)
self.reCenter()
self.checkTimeout()
self.setSolution(self.getAnswer())
pDone=float(maxtemp - temp)/(maxtemp-mintemp)
self.setStatusDone(str(math.floor(pDone*100))+"% | "+self.remainingTime(pDone))
elif (temp <= mintemp):
dyn = FIRE(atoms=self.particle)
dyn.run(fmax=0.01)
self.bestEnergy = self.particle.get_potential_energy()
self.bestParticle = deepcopy(self.particle)
self.reCenter()
self.setSolution(self.getAnswer())
pDone=float(temp)/(maxtemp-mintemp)
self.setStatusDone(str(math.floor(pDone*100))+"% | "+self.remainingTime(pDone))
return self.getAnswer()
def main():
from time import time
#t0 = time()
#write('POSCAR', make_pamam(4))
#t1 = time()
#print t1-t0
from ase.io import read
print 'reading structure'
atoms = read('PAMAM-G4.xyz')
print 'building bonds'
bonds = connect_bonds(atoms)
calc = VSEPR(atoms, bonds)
atoms.set_calculator(calc)
t0 = time()
opt = FIRE(atoms, trajectory='opt.traj')
opt.run(fmax=1e-3, steps=1000)
t1 = time()
print 'time:',t1-t0
def test_CuZr(self):
# This is a test for the potential published in:
# Mendelev, Sordelet, Kramer, J. Appl. Phys. 102, 043501 (2007)
a = FaceCenteredCubic('Cu', size=[2, 2, 2])
calc = EAM('CuZr_mm.eam.fs', kind='eam/fs')
a.set_calculator(calc)
FIRE(StrainFilter(a, mask=[1, 1, 1, 0, 0, 0]),
logfile=None).run(fmax=0.001)
a_Cu = a.cell.diagonal().mean() / 2
#print('a_Cu (3.639) = ', a_Cu)
self.assertAlmostEqual(a_Cu, 3.639, 3)
a = HexagonalClosedPacked('Zr', size=[2, 2, 2])
a.set_calculator(calc)
FIRE(StrainFilter(a, mask=[1, 1, 1, 0, 0, 0]),
logfile=None).run(fmax=0.001)
a, b, c = a.cell / 2
#print('a_Zr (3.220) = ', norm(a), norm(b))
#print('c_Zr (5.215) = ', norm(c))
self.assertAlmostEqual(norm(a), 3.220, 3)
self.assertAlmostEqual(norm(b), 3.220, 3)
self.assertAlmostEqual(norm(c), 5.215, 3)
# CuZr3
a = L1_2(['Cu', 'Zr'], size=[2, 2, 2], latticeconstant=4.0)
a.set_calculator(calc)
FIRE(UnitCellFilter(a, mask=[1, 1, 1, 0, 0, 0]),
logfile=None).run(fmax=0.001)
self.assertAlmostEqual(a.cell.diagonal().mean() / 2, 4.324, 3)
# Cu3Zr
a = L1_2(['Zr', 'Cu'], size=[2, 2, 2], latticeconstant=4.0)
a.set_calculator(calc)
FIRE(UnitCellFilter(a, mask=[1, 1, 1, 0, 0, 0]),
logfile=None).run(fmax=0.001)
self.assertAlmostEqual(a.cell.diagonal().mean() / 2, 3.936, 3)
# CuZr
a = B2(['Zr', 'Cu'], size=[2, 2, 2], latticeconstant=3.3)
a.set_calculator(calc)
FIRE(UnitCellFilter(a, mask=[1, 1, 1, 0, 0, 0]),
logfile=None).run(fmax=0.001)
self.assertAlmostEqual(a.cell.diagonal().mean() / 2, 3.237, 3)
def test_hessian_divide_by_masses(self):
"""
Test the computation of the Hessian matrix
"""
atoms = FaceCenteredCubic('H', size=[2,2,2], latticeconstant=2.37126)
atoms.set_array("size", np.random.uniform(1.0, 2.22, size=len(atoms)), dtype=float)
masses_n = np.random.randint(1, 10, size=len(atoms))
atoms.set_masses(masses=masses_n)
calc = Polydisperse(InversePowerLawPotential(1.0, 1.4, 0.1, 3, 1, 2.22))
atoms.set_calculator(calc)
dyn = FIRE(atoms)
dyn.run(fmax=1e-5)
D_analytical = calc.hessian_matrix(atoms, divide_by_masses=True)
D_analytical = D_analytical.todense()
H_analytical = calc.hessian_matrix(atoms)
H_analytical = H_analytical.todense()
masses_nc = masses_n.repeat(3)
H_analytical /= np.sqrt(masses_nc.reshape(-1,1)*masses_nc.reshape(1,-1))
self.assertArrayAlmostEqual(H_analytical, D_analytical, tol=self.tol)
def make_methylamine():
# Construct Methylamine.
atoms = ase.Atoms('NH2CH3')
# Define connectivity.
atoms_bonds = [ [0,1], [0,2], [0,3], [3,4], [3,5], [3,6] ]
# Displace atoms so that they aren't on top of each other.
atoms.rattle(0.001)
# Construct VSEPR calculator.
calculator = VSEPR(atoms, atoms_bonds)
atoms.set_calculator(calculator)
atoms.center()
# Run optimization.
opt = FIRE(atoms)
opt.run()
return atoms
def test_Grochola(self):
a = FaceCenteredCubic('Au', size=[2,2,2])
calc = EAM('Au-Grochola-JCP05.eam.alloy')
a.set_calculator(calc)
FIRE(StrainFilter(a, mask=[1,1,1,0,0,0]), logfile=None).run(fmax=0.001)
a0 = a.cell.diagonal().mean()/2
self.assertTrue(abs(a0-4.0701)<2e-5)
self.assertTrue(abs(a.get_potential_energy()/len(a)+3.924)<0.0003)
C, C_err = fit_elastic_constants(a, symmetry='cubic', verbose=False)
C11, C12, C44 = Voigt_6x6_to_cubic(C)
self.assertTrue(abs((C11-C12)/GPa-32.07)<0.7)
self.assertTrue(abs(C44/GPa-45.94)<0.5)
def breedParticles(self, particle1, particle2):
index = 0;
mindistance = 0;
bestatom = None;
for atom in particle1:
mindistance = 1000000.;
bestatom = None;
if(random.random() < 0.5):
for atom2 in particle2:
if(atom2.symbol == atom.symbol and (atom.position[0] - atom2.position[0])**2 + (atom.position[1] - atom2.position[1])**2 + (atom.position[2] - atom2.position[2])**2 < mindistance**2):
mindistance = ((atom.position[0] - atom2.position[0])**2 + (atom.position[1] - atom2.position[1])**2 + (atom.position[2] - atom2.position[2])**2)**0.5;
bestatom = deepcopy(atom2);
atom.x = bestatom.position[0] + random.gauss(0.,0.25);
atom.y = bestatom.position[1] + random.gauss(0.,0.25);
atom.z = bestatom.position[2] + random.gauss(0.,0.25);
particle1.get_potential_energy()
sys.stdout = f
dyn = FIRE(atoms=particle1)
dyn.run()
sys.stdout = std_outpath
return particle1;
def surface_energy(surface, calc, accuracy=0.00001, shake=0.1, seed=1):
"""
calculates the energy of the surface (without dividing by the area or subtracting bulk)
Note: we will calculate the bulk energy for one atom and multiply by number of atoms to save time in calculation
"""
symbol = surface.get_chemical_symbols()[0]
surface.set_calculator(calc)
e_surface = surface.get_potential_energy()
print "unrelaxed energy:", e_surface
# rattle surface atoms a bit, to relax, get relaxed energy
surface.rattle(stdev=shake,seed=seed)
dyn = FIRE(surface)
dyn.run(fmax=accuracy)
e_relaxed_surface = surface.get_potential_energy()
return e_surface, e_relaxed_surface
def relax(self):
"""Relax the atoms return the relaxed energy.
This function leaves the atoms unchanged (it changes them
but restores the positions).
If a single atoms moves "too much" the relaxation is rejected.
"""
if self.atoms.get_calculator().__class__.__name__ == 'adscalc':
self.atoms.get_calculator().use_adsorbates(False)
energy_before = self.atoms.get_potential_energy()
#print "unrelaxed energy: "+str(energy)
old_pos = self.atoms.get_positions()
for i in range(3):
dyn = FIRE(atoms=self.atoms, logfile=None)
dyn.run(fmax=0.05, steps=2000)
reten = self.atoms.get_potential_energy()
# Sanity check.
nblist = self.atoms.get_calculator().get_neighbor_list()
r = self.atoms.get_positions() - old_pos
dr = np.zeros((len(self.atoms), 3))
for i in range(len(self.atoms)):
nblist_i = nblist[i]
dr[i] = r - r[nblist_i].sum(axis=0) / len(nblist[i])
dr = np.sqrt((dr * dr).sum(axis=1).max())
# dr is now how far the most mobile atom has moved
# relative to its neighbors.
# Now, identify how far it is reasonable that it has moved.
x = old_pos[0] - old_pos[nblist[0]]
acceptable = np.sqrt((x * x).sum(axis=1).min())
assert acceptable > 0.01
if dr > 0.5 * acceptable:
reten = energy_before # Reject
# Restore the atoms
self.atoms.set_positions(old_pos)
if self.atoms.get_calculator().__class__.__name__ == 'adscalc':
self.atoms.get_calculator().use_adsorbates(True)
return energy_before, reten
def Minimisation_Function(cluster,collection,cluster_name):
####################################################################################################################
cluster.pbc = False
####################################################################################################################
# Perform the local optimisation method on the cluster.
# Parameter sequence: [p, q, a, xi, r0]
#Gupta_parameters = {'Au': [10.529999999999999, 4.2999999999999998, 0.21970000000000001, 1.855, 2.8779245994292486]}
Gupta_parameters = {'Pd': [10.867, 3.742, 0.1746, 1.718, 2.7485], 'Au': [10.229, 4.036, 0.2061, 1.79, 2.884], ('Au','Pd'): [10.54, 3.89, 0.19, 1.75, 2.816]}
cluster.set_calculator(Gupta(Gupta_parameters, cutoff=1000, debug=False))
dyn = FIRE(cluster,logfile=None)
startTime = time.time(); converged = False
try:
dyn.run(fmax=0.01,steps=5000)
converged = dyn.converged()
if not converged:
errorMessage = 'The optimisation of cluster ' + str(cluster_name) + ' did not optimise completely.'
print(errorMessage, file=sys.stderr)
print(errorMessage)
except Exception:
print('Local Optimiser Failed for some reason.')
endTime = time.time()
####################################################################################################################
# Write information about the algorithm
Info = {}
Info["INFO.txt"] = ''
Info["INFO.txt"] += ("No of Force Calls: " + str(dyn.get_number_of_steps()) + '\n')
Info["INFO.txt"] += ("Time (s): " + str(endTime - startTime) + '\n')
#Info["INFO.txt"] += ("Cluster converged?: " + str(dyn.converged()) + '\n')
####################################################################################################################
return cluster, converged, Info
def Minimisation_Function(cluster, collection, cluster_dir):
cluster.pbc = False
rCut = 1000
#sigma = 1; epsilon = 1; lj_calc = LennardJones(sigma=sigma, epsilon=epsilon,rc=rCut)
elements = [atomic_numbers[cluster[0].symbol]]
sigma = [1]
epsilon = [1]
lj_calc = LennardJones(elements, epsilon, sigma, rCut=rCut, modified=True)
cluster.set_calculator(lj_calc)
dyn = FIRE(cluster, logfile=None)
startTime = time.time()
converged = False
try:
dyn.run(fmax=0.01, steps=5000)
converged = dyn.converged()
if not converged:
errorMessage = 'The optimisation of cluster ' + str(
cluster_dir) + ' did not optimise completely.'
print(errorMessage, file=sys.stderr)
print(errorMessage)
except Exception:
print('Local Optimiser Failed for some reason.')
endTime = time.time()
# Write information about the algorithm
Info = {}
Info["INFO.txt"] = ''
Info["INFO.txt"] += ("No of Force Calls: " +
str(dyn.get_number_of_steps()) + '\n')
Info["INFO.txt"] += ("Time (s): " + str(endTime - startTime) + '\n')
#Info.write("Cluster converged?: " + str(dyn.converged()) + '\n')
return cluster, converged, Info
def Minimisation_Function(cluster, collection, cluster_name):
cluster.pbc = False
####################################################################################################################
# Perform the local optimisation method on the cluster.
# Parameter sequence: [p, q, a, xi, r0]
Gupta_parameters = {'Cu': [10.960, 2.2780, 0.0855, 1.224, 2.556]}
cluster.set_calculator(Gupta(Gupta_parameters, cutoff=1000, debug=False))
dyn = FIRE(cluster, logfile=None)
startTime = time.time()
converged = False
try:
dyn.run(fmax=0.01, steps=5000)
converged = dyn.converged()
if not converged:
errorMessage = 'The optimisation of cluster ' + str(
cluster_name) + ' did not optimise completely.'
print(errorMessage, file=sys.stderr)
print(errorMessage)
except:
print('Local Optimiser Failed for some reason.')
endTime = time.time()
####################################################################################################################
# Write information about the algorithm
Info = {}
Info["INFO.txt"] = ''
Info["INFO.txt"] += ("No of Force Calls: " +
str(dyn.get_number_of_steps()) + '\n')
Info["INFO.txt"] += ("Time (s): " + str(endTime - startTime) + '\n')
#Info["INFO.txt"] += ("Cluster converged?: " + str(dyn.converged()) + '\n')
####################################################################################################################
return cluster, converged, Info
def relax_defect_cell(self,
ats,
output_name='defect_cell_relaxed.xyz',
force_tol=0.0001,
relax_cell=False):
"""
Accepts atoms object with an attached calculator.Minimize forces.
Args:
ats (:obj:`Atoms`): Atoms with defect to relax.
output_name (str, optional): Filename to print relaxed atoms structure to.
force_tol (float, optional): Force tolerance to stop relaxation.
relax_cell (bool, optional): Relax lattice parameters.
Returns:
:class:`Atoms`: A relaxed Atoms object.
"""
from ase.optimize import FIRE
if relax_cell:
strain_mask = [1, 1, 1, 0, 0, 0]
ucf = UnitCellFilter(ats, strain_mask)
opt = FIRE(ucf)
else:
strain_mask = [0, 0, 0, 0, 0, 0]
ucf = UnitCellFilter(ats, strain_mask)
opt = FIRE(ucf)
opt.run(fmax=force_tol)
ats.write(output_name)
return ats
def relax(self):
"""Relax the atoms return the relaxed energy.
This function leaves the atoms unchanged (it changes them
but restores the positions).
If a single atoms moves "too much" the relaxation is rejected.
"""
if self.atoms.get_calculator().__class__.__name__ == 'adscalc':
self.atoms.get_calculator().use_adsorbates(False)
energy_before = self.atoms.get_potential_energy()
#print "unrelaxed energy: "+str(energy)
old_pos = self.atoms.get_positions()
for i in range(3):
dyn = FIRE(atoms=self.atoms,logfile=None)
dyn.run(fmax=0.05, steps=2000)
reten=self.atoms.get_potential_energy()
# Sanity check.
nblist = self.atoms.get_calculator().get_neighbor_list()
r = self.atoms.get_positions() - old_pos
dr = np.zeros((len(self.atoms),3))
for i in range(len(self.atoms)):
nblist_i = nblist[i]
dr[i] = r - r[nblist_i].sum(axis=0)/len(nblist[i])
dr = np.sqrt( (dr*dr).sum(axis=1).max() )
# dr is now how far the most mobile atom has moved
# relative to its neighbors.
# Now, identify how far it is reasonable that it has moved.
x = old_pos[0] - old_pos[nblist[0]]
acceptable = np.sqrt( (x*x).sum(axis=1).min() )
assert acceptable > 0.01
if dr > 0.5 * acceptable:
reten = energy_before # Reject
# Restore the atoms
self.atoms.set_positions(old_pos)
if self.atoms.get_calculator().__class__.__name__ == 'adscalc':
self.atoms.get_calculator().use_adsorbates(True)
return energy_before, reten
def surface_energy(surface, calc, accuracy=0.00001, shake=0.1, seed=1):
"""
calculates the energy of the surface (without dividing by the area or subtracting bulk)
Note: we will calculate the bulk energy for one atom and multiply by number of atoms to save time in calculation
"""
symbol = surface.get_chemical_symbols()[0]
surface.set_calculator(calc)
pos_unrelaxed = surface.positions[:]
e_surface = surface.get_potential_energy()
print "unrelaxed energy:", e_surface
# rattle surface atoms a bit, to relax, get relaxed energy
surface.rattle(stdev=shake, seed=seed)
dyn = FIRE(surface)
dyn.run(fmax=accuracy)
e_relaxed_surface = surface.get_potential_energy()
pos_relaxed = surface.positions[:]
return e_surface, e_relaxed_surface, pos_unrelaxed, pos_relaxed
def relax_structure(atoms, relax_fmax=0.05, traj_interval=None):
"""
Relax atoms object. If it contains a 'fixed_mask' array, then run constrained relaxation
"""
arel = atoms.copy()
try:
fix_mask = atoms.get_array("fixed_mask")
print("Running relaxation with %d constrained atoms" % fix_mask.sum())
const = FixAtoms(mask=fix_mask)
arel.set_constraint(const)
except:
print("No constraints specified, running relaxation")
arel.set_calculator(calc)
opt = FIRE(arel) # LBFGS(arel) #
if traj_interval is not None:
from quippy.io import AtomsWriter
out = AtomsWriter("traj-relax_structure.xyz")
trajectory_write = lambda: out.write(QAtoms(arel, charge=None))
opt.attach(trajectory_write, interval=traj_interval)
opt.run(fmax=relax_fmax)
return arel
import sys
sys.path.insert(0, '.')
import params
a = params.cryst.copy()
# ***** Find eqm. lattice constant ******
# find the equilibrium lattice constant by minimising atoms wrt virial
# tensor given by SW pot (possibly replace this with parabola fit in
# another script and hardcoded a0 here)
a.set_calculator(params.calc)
if hasattr(params, 'relax_bulk') and params.relax_bulk:
print('Minimising bulk unit cell...')
opt = FIRE(StrainFilter(a, mask=[1, 1, 1, 0, 0, 0]))
opt.run(fmax=params.bulk_fmax)
a0 = a.cell[0, 0]
print('Lattice constant %.3f A\n' % a0)
a.set_calculator(params.calc)
# ******* Find elastic constants *******
# Get 6x6 matrix of elastic constants C_ij
C = measure_triclinic_elastic_constants(a, optimizer=FIRE,
fmax=params.bulk_fmax)
print('Elastic constants (GPa):')
print((C / units.GPa).round(0))
print('')
fix_atoms = FixAtoms(mask=fixed_mask)
print('Fixed atoms: %d\n' % fixed_mask.sum())
# Increase epsilon_yy applied to all atoms at constant strain rate
strain_atoms = ConstantStrainRate(orig_height,
params.strain_rate*params.timestep)
atoms.set_constraint([fix_atoms, strain_atoms])
atoms.set_calculator(params.calc)
# Save frames to the trajectory every `traj_interval` time steps
traj_file = open('traj-m-6r.xyz', 'w')
minimiser = FIRE(atoms, restart='hess.traj')
def trajectory_write():
ase.io.extxyz.write_xyz(traj_file, atoms)
# swap is an array of atom indices that have to be sent in opposite direction wrt
# what thin_strip_displacement_y would do.
swap = np.loadtxt('swap_topbottom_atoms.csv')
for i in range(1000):
minimiser.run(fmax=params.relax_fmax)
trajectory_write()
# Find initial position of crack tip
#crack_pos = find_tip_stress_field(crack_slab, calc=params.calc)
#print 'Found crack tip at position %s' % crack_pos
image.constraints.append(constraint)
# Displace last image:
for i in xrange(1,8,1):
images[-1].positions[-i] += (d/2, -h1/3, 0)
write('initial.traj', images[0])
# Relax height of Ag atom for initial and final states:
for image in [images[0], images[-1]]:
QuasiNewton(image).run(fmax=0.01)
if 0:
write('initial.pckl', image[0])
write('finial.pckl', image[-1])
# Interpolate positions between initial and final states:
neb.interpolate()
for image in images:
print image.positions[-1], image.get_potential_energy()
traj = PickleTrajectory('mep.traj', 'w')
dyn = FIRE(neb, dt=0.1)
#dyn = MDMin(neb, dt=0.1)
#dyn = QuasiNewton(neb)
dyn.attach(neb.writer(traj))
dyn.run(fmax=0.01,steps=150)
for image in images:
print image.positions[-1], image.get_potential_energy()
mol = Cluster([Atom('H'),
Atom('H',[1,0,0]),
Atom('H',[.5,.5,.5])],
cell = [2,2,2],
pbc=True)
def set_calculators(all=False):
c=GPAW(h=.3, convergence={'eigenstates':0.1,
'energy' : 0.1,
'density' : 0.01}, txt=txt)
# c = EMT()
n = len(images)
if not all:
n -= 2
neb.set_calculators([c] * n)
images = [mol]
for i in range(4):
images.append(images[0].copy())
images[-1].positions[2, 1] = 2 - images[0].positions[2, 1]
neb = SingleCalculatorNEB(images)
neb.interpolate()
for image in images:
print(image[2].position)
set_calculators(True)
dyn = FIRE(neb, trajectory='mep.traj')
dyn.insert_observer(set_calculators)
print(dyn.run(fmax=8.))
cell = surf_cell.get_cell()
A = cell[0][0]*cell[1][1]
gamma = (surf_ener- len(surf_cell)*ener_per_atom)/A
print '2*gamma ev/A2', gamma
print '2*gamma J/m2', gamma/(units.J/units.m**2)
j_dict = {'or_axis':or_axis, 'bp':bp, 'gamma':gamma}
with open('gbfrac.json','w') as f:
json.dump(j_dict, f)
out = AtomsWriter('{0}'.format('{0}_surf.xyz'.format(gbid)))
out.write(Atoms(surf_cell))
out.close()
frac_cell = gb_frac.build_tilt_sym_frac()
#Unit cell for grain boundary fracture cell:
print frac_cell.get_cell().round(2)
frac_cell = Atoms(frac_cell)
frac_cell = del_atoms(frac_cell)
#Relax grainboundary crack cell unit cell:
pot = Potential('IP EAM_ErcolAd', param_filename='Fe_Mendelev.xml')
frac_cell.set_calculator(pot)
slab_opt = FIRE(frac_cell)
slab_opt.run(fmax = (0.02*units.eV/units.Ang))
#Print frac_cell to file:
out = AtomsWriter('{0}'.format('frac_cell.xyz'.format(gbid)))
out.write(Atoms(frac_cell))
out.close()
C 5.750174626862403 4.162261915959347 4.240449977068684
C 7.150130182125531 4.155384186721486 4.537328602062397
H 3.218154657585170 4.565210696328925 3.522601038049320
H 3.077656122062729 6.375092902842770 3.826039498180272
H 5.478464901706067 6.370680001794822 4.422235395756437
H 5.320549047980879 3.220584852467720 3.974551561510350
H 7.723359150977955 3.224855971783890 4.574146712279462
H 7.580803493981530 5.034479218283977 4.877211530909463
"""
h = 0.3
atoms = Cluster(read_xyz(StringIO.StringIO(butadiene)))
atoms.minimal_box(3.0, h)
atoms.set_calculator(GPAW(h=h))
if 0:
dyn = FIRE(atoms)
dyn.run(fmax=0.05)
atoms.write("butadiene.xyz")
vibname = "fcvib"
vib = Vibrations(atoms, name=vibname)
vib.run()
# Modul
a = FranckCondon(atoms, vibname, minfreq=250)
# excited state forces
F = np.array(
[
[-2.11413, 0.07317, -0.91682],
[3.23569, -0.74520, 0.76758],
def opt(atoms, bonds):
atoms.rattle()
calculator = VSEPR(atoms, bonds)
atoms.set_calculator(calculator)
opt = FIRE(atoms, dtmax=0.5, logfile='/dev/null', trajectory='opt.traj')
opt.run(fmax=0.1)
def voids(atoms_in):
"""Find location and size of voids in a given structure.
Returns the voids as 'X' atoms. The atoms' charge is misused
to contain the voids' radius.
"""
trials = 6 # XXX do not hardwire
atoms = atoms_in.copy()
# append moving atom
atoms.append(Atom('X'))
atoms.set_calculator(RepulsivePotential())
voids_a = Atoms()
voids_a.set_cell(atoms.get_cell())
voids_a.set_pbc(atoms.get_pbc())
positions = atoms.get_positions()
for pos in positions[:-1]:
for c in range(trials):
positions[-1] = pos + 0.1 * np.random.uniform(-1, 1, size=3)
atoms.set_positions(positions)
# XXX do not hardwire
relax = FIRE(atoms,
logfile=None
)
# XXX do not hardwire
relax.run(fmax=0.001, steps=100)
# get minimal distance
Rmin = 100000
for b in range(len(atoms) - 1):
R = atoms.get_distance(b, -1, mic=True)
if R < Rmin:
Rmin = R
# check if new or better
voids_a.append(Atom('X',
atoms.get_positions()[-1],
charge=Rmin))
voids_a.set_positions(voids_a.get_positions(wrap=True))
remove = []
last = len(voids_a) - 1
for ia, a in enumerate(voids_a[:-1]):
d = voids_a.get_distance(ia, -1, mic=True)
if d < a.charge or d < Rmin:
if a.charge > Rmin:
remove.append(last)
else:
remove.append(ia)
remove.sort()
if last not in remove:
p = voids_a.get_positions()[-1]
print('found new void at [%g,%g,%g], R=%g' %
(p[0], p[1], p[2], Rmin))
for a in remove[::-1]:
if a != last:
p = voids_a.get_positions()[a]
print('removing void at [%g,%g,%g], R=%g' %
(p[0], p[1], p[2], voids_a[a].charge))
voids_a.pop(a)
return voids_a
f_ext = 0.2
atom1 = 0
atom2 = 1
atom3 = 2
fmax = 0.001
atoms = Atoms('H3', positions=[(0, 0, 0), (0.751, 0, 0), (0, 1., 0)])
atoms.set_calculator(EMT())
# Without external force
opt = FIRE(atoms)
opt.run(fmax=fmax)
dist1 = atoms.get_distance(atom1, atom2)
# With external force
con1 = ExternalForce(atom1, atom2, f_ext)
atoms.set_constraint(con1)
opt = FIRE(atoms)
opt.run(fmax=fmax)
dist2 = atoms.get_distance(atom1, atom2)
# Distance should increase due to the external force
assert dist2 > dist1
# Combine ExternalForce with FixBondLength
# Fix the bond on which the force acts
import numpy as np
from ase.calculators.emt import EMT
from ase.build import bulk
from ase.optimize import FIRE
a = bulk('Au')
a *= (2, 2, 2)
a[0].x += 0.5
a.set_calculator(EMT())
opt = FIRE(a, dtmax=1.0, dt=1.0, maxmove=100.0, downhill_check=False)
opt.run(fmax=0.001)
e1 = a.get_potential_energy()
n1 = opt.nsteps
a = bulk('Au')
a *= (2, 2, 2)
a[0].x += 0.5
a.set_calculator(EMT())
reset_history = []
def callback(a, r, e, e_last):
reset_history.append([e - e_last])
image.set_calculator(LennardJones())
images.append(image)
images.append(final)
# Define the NEB and make a linear interpolation
# with removing translational
# and rotational degrees of freedom
neb = NEB(images,
remove_rotation_and_translation=remove_rotation_and_translation)
neb.interpolate()
# Test used these old defaults which are not optimial, but work
# in this particular system
neb.idpp_interpolate(fmax=0.1, optimizer=BFGS)
qn = FIRE(neb, dt=0.005, maxmove=0.05, dtmax=0.1)
qn.run(steps=20)
# Switch to CI-NEB, still removing the external degrees of freedom
# Also spesify the linearly varying spring constants
neb = NEB(images, climb=True,
remove_rotation_and_translation=remove_rotation_and_translation)
qn = FIRE(neb, dt=0.005, maxmove=0.05, dtmax=0.1)
qn.run(fmax=fmax)
images = neb.images
nebtools = NEBTools(images)
Ef_neb, dE_neb = nebtools.get_barrier(fit=False)
nsteps_neb = qn.nsteps
if remove_rotation_and_translation:
# object and attach a calculator (QSC).
###########################################################
atoms = makeBimetallic('POSCAR',100,78,79,0.5)
calc = QSC()
atoms.set_calculator(calc)
minimaList = PickleTrajectory('Pt75Au25.traj',mode='a')
for i in range(NMoves):
numbertomove = numpy.random.randint(len(atoms))
atoms = moveAtoms(numbertomove,atoms)
atoms.center()
atoms = preventExplosions(atoms)
# do a last optimization of the structure
dyn = FIRE(atoms)
dyn.run()
newEnergy = atoms.get_potential_energy()
if (newEnergy < bestEnergy):
bestEnergy = newEnergy
line = str(totalMinimaFound) + " " + str(atoms.get_potential_energy()) + " " + str(i) +"\n"
print line
f = open('EnergyList.txt','a')
f.write(line)
f.close()
minimaList.write(atoms)
totalMinimaFound += 1
sinceLastFind = 0
elif (sinceLastFind < 200): # if we haven't found a new minimum in 200 tries, start over
atoms = ase.io.read('POSCAR')
calc = QSC()
print 'Running WITH EAM as embedded cluster'
qm_pot_file = os.path.join(pot_dir, 'PotBH_fakemod.xml')
print qm_pot_file
mm_init_args = 'IP EAM_ErcolAd do_rescale_r=T r_scale=1.01' # Classical potential
qm_pot = Potential(mm_init_args, param_filename=qm_pot_file, cutoff_skin=cutoff_skin)
qmmm_pot = set_qmmm_pot(atoms, atoms.params['CrackPos'], mm_pot, qm_pot)
strain_atoms = fix_edges(atoms)
print 'Setup dynamics'
#If input_file is crack.xyz the cell has not been thermalized yet.
#Otherwise it will recover temperature from the previous run.
print 'Attaching trajectories to dynamics'
trajectory = AtomsWriter(traj_file)
#Only wriates trajectory if the system is in the LOTFDynamicas
#Interpolation
atoms.wrap()
atoms.set_cutoff(3.0)
atoms.calc_connect()
print 'Running Crack Simulation'
RELAXATION = False
if RELAXATION:
dynamics = FIRE(atoms)
dynamics.attach(pass_trajectory_context(trajectory, dynamics), traj_interval, dynamics)
dynamics.run(fmax=0.1)
else:
dynamics = LOTFDynamics(atoms, timestep, extrapolate_steps)
dynamics.attach(pass_trajectory_context(trajectory, dynamics), traj_interval, dynamics)
nsteps = 2000
dynamics.run(nsteps)
def test_J_integral(self):
"""
Check if the J-integral returns G=2*gamma
"""
if not atomistica:
print 'Atomistica not available. Skipping test.'
nx = 128
for calc, a0, C11, C12, C44, surface_energy, bulk_coordination in [
( atomistica.DoubleHarmonic(k1=1.0, r1=1.0, k2=1.0,
r2=math.sqrt(2), cutoff=1.6),
clusters.sc('He', 1.0, [nx,nx,1], [1,0,0], [0,1,0]),
3, 1, 1, 0.05, 6 ),
# ( atomistica.Harmonic(k=1.0, r0=1.0, cutoff=1.3, shift=False),
# clusters.fcc('He', math.sqrt(2.0), [nx/2,nx/2,1], [1,0,0],
# [0,1,0]),
# math.sqrt(2), 1.0/math.sqrt(2), 1.0/math.sqrt(2), 0.05, 12)
]:
print '{} atoms.'.format(len(a0))
crack = CubicCrystalCrack(C11, C12, C44, [1,0,0], [0,1,0])
x, y, z = a0.positions.T
r2 = min(np.max(x)-np.min(x), np.max(y)-np.min(y))/4
r1 = r2/2
a = a0.copy()
a.center(vacuum=20.0, axis=0)
a.center(vacuum=20.0, axis=1)
ref = a.copy()
r0 = ref.positions
a.set_calculator(calc)
print 'epot = {}'.format(a.get_potential_energy())
sx, sy, sz = a.cell.diagonal()
tip_x = sx/2
tip_y = sy/2
k1g = crack.k1g(surface_energy)
g = a.get_array('groups')
old_x = tip_x+1.0
old_y = tip_y+1.0
while abs(tip_x-old_x) > 1e-6 and abs(tip_y-old_y) > 1e-6:
a.set_constraint(None)
ux, uy = crack.displacements(r0[:,0], r0[:,1], tip_x, tip_y,
k1g)
a.positions[:,0] = r0[:,0] + ux
a.positions[:,1] = r0[:,1] + uy
a.positions[:,2] = r0[:,2]
a.set_constraint(ase.constraints.FixAtoms(mask=g==0))
opt = FIRE(a, logfile=None)
opt.run(fmax=1e-3)
old_x = tip_x
old_y = tip_y
tip_x, tip_y = crack.crack_tip_position(a.positions[:,0],
a.positions[:,1],
r0[:,0], r0[:,1],
tip_x, tip_y, k1g,
mask=g!=0)
print tip_x, tip_y
# Get atomic strain
i, j = neighbour_list("ij", a, cutoff=1.3)
deformation_gradient, residual = \
atomic_strain(a, ref, neighbours=(i, j))
# Get atomic stresses
# Note: get_stresses returns the virial in Atomistica!
virial = a.get_stresses()
virial = Voigt_6_to_full_3x3_stress(virial)
# Compute J-integral
epot = a.get_potential_energies()
eref = np.zeros_like(epot)
for r1, r2 in [(r1, r2), (r1/2, r2/2), (r1/2, r2)]:
print 'r1 = {}, r2 = {}'.format(r1, r2)
J = J_integral(a, deformation_gradient, virial, epot, eref,
tip_x, tip_y, r1, r2)
print '2*gamma = {0}, J = {1}'.format(2*surface_energy, J)
