def create_random_atoms(gd, nmolecules=10, name='NH2', mindist=4.5 / Bohr):
"""Create gas-like collection of atoms from randomly placed molecules.
Applies rigid motions to molecules, translating the COM and/or rotating
by a given angle around an axis of rotation through the new COM. These
atomic positions obey the minimum distance requirement to zero-boundaries.
Warning: This is only intended for testing parallel grid/LFC consistency.
"""
atoms = Atoms(cell=gd.cell_cv * Bohr, pbc=gd.pbc_c)
# Store the original state of the random number generator
randstate = np.random.get_state()
seed = np.array([md5_array(data, numeric=True)
for data in
[nmolecules, gd.cell_cv, gd.pbc_c, gd.N_c]]).astype(int)
np.random.seed(seed % 4294967296)
for m in range(nmolecules):
amol = molecule(name)
amol.set_cell(gd.cell_cv * Bohr)
# Rotate the molecule around COM according to three random angles
# The rotation axis is given by spherical angles phi and theta
v,phi,theta = np.random.uniform(0.0, 2*np.pi, 3) # theta [0,pi[ really
axis = np.array([cos(phi)*sin(theta), sin(phi)*sin(theta), cos(theta)])
amol.rotate(axis, v)
# Find the scaled length we must transverse along the given axes such
# that the resulting displacement vector is `mindist` from the cell
# face corresponding to that direction (plane with unit normal n_v).
sdist_c = np.empty(3)
if not gd.orthogonal:
for c in range(3):
n_v = gd.xxxiucell_cv[c] / np.linalg.norm(gd.xxxiucell_cv[c])
sdist_c[c] = mindist / np.dot(gd.cell_cv[c], n_v)
else:
sdist_c[:] = mindist / gd.cell_cv.diagonal()
assert np.all(sdist_c > 0), 'Displacment vectors must be inside cell.'
# Scaled dimensions of the smallest possible box centered on the COM
spos_ac = amol.get_scaled_positions() # NB! must not do a "% 1.0"
scom_c = np.dot(gd.icell_cv, amol.get_center_of_mass())
sbox_c = np.abs(spos_ac-scom_c[np.newaxis,:]).max(axis=0)
sdelta_c = (1-np.array(gd.pbc_c)) * (sbox_c + sdist_c)
assert (sdelta_c < 1.0-sdelta_c).all(), 'Box is too tight to fit atoms.'
scenter_c = [np.random.uniform(d,1-d) for d in sdelta_c]
center_v = np.dot(scenter_c, gd.cell_cv)
# Translate the molecule such that COM is located at random center
offset_av = (center_v-amol.get_center_of_mass()/Bohr)[np.newaxis,:]
amol.set_positions(amol.get_positions()+offset_av*Bohr)
assert np.linalg.norm(center_v-amol.get_center_of_mass()/Bohr) < 1e-9
atoms.extend(amol)
# Restore the original state of the random number generator
np.random.set_state(randstate)
assert compare_atoms(atoms)
return atoms
def create_random_atoms(gd, nmolecules=10, name='H2O', mindist=4.5 / Bohr):
"""Create gas-like collection of atoms from randomly placed molecules.
Applies rigid motions to molecules, translating the COM and/or rotating
by a given angle around an axis of rotation through the new COM. These
atomic positions obey the minimum distance requirement to zero-boundaries.
Warning: This is only intended for testing parallel grid/LFC consistency.
"""
atoms = Atoms(cell=gd.cell_cv * Bohr, pbc=gd.pbc_c)
# Store the original state of the random number generator
randstate = np.random.get_state()
np.random.seed(np.array([md5_array(data, numeric=True) for data
in [nmolecules, gd.cell_cv, gd.pbc_c, gd.N_c]]).astype(int))
for m in range(nmolecules):
amol = molecule(name)
amol.set_cell(gd.cell_cv * Bohr)
# Rotate the molecule around COM according to three random angles
# The rotation axis is given by spherical angles phi and theta
v,phi,theta = np.random.uniform(0.0, 2*np.pi, 3) # theta [0,pi[ really
axis = np.array([cos(phi)*sin(theta), sin(phi)*sin(theta), cos(theta)])
amol.rotate(axis, v)
# Find the scaled length we must transverse along the given axes such
# that the resulting displacement vector is `mindist` from the cell
# face corresponding to that direction (plane with unit normal n_v).
sdist_c = np.empty(3)
if not gd.orthogonal:
for c in range(3):
n_v = gd.xxxiucell_cv[c] / np.linalg.norm(gd.xxxiucell_cv[c])
sdist_c[c] = mindist / np.dot(gd.cell_cv[c], n_v)
else:
sdist_c[:] = mindist / gd.cell_cv.diagonal()
assert np.all(sdist_c > 0), 'Displacment vectors must be inside cell.'
# Scaled dimensions of the smallest possible box centered on the COM
spos_ac = amol.get_scaled_positions() # NB! must not do a "% 1.0"
scom_c = np.dot(gd.icell_cv, amol.get_center_of_mass())
sbox_c = np.abs(spos_ac-scom_c[np.newaxis,:]).max(axis=0)
sdelta_c = (1-np.array(gd.pbc_c)) * (sbox_c + sdist_c)
assert (sdelta_c < 1.0-sdelta_c).all(), 'Box is too tight to fit atoms.'
scenter_c = [np.random.uniform(d,1-d) for d in sdelta_c]
center_v = np.dot(scenter_c, gd.cell_cv)
# Translate the molecule such that COM is located at random center
offset_av = (center_v-amol.get_center_of_mass()/Bohr)[np.newaxis,:]
amol.set_positions(amol.get_positions()+offset_av*Bohr)
assert np.linalg.norm(center_v-amol.get_center_of_mass()/Bohr) < 1e-9
atoms.extend(amol)
# Restore the original state of the random number generator
np.random.set_state(randstate)
assert compare_atoms(atoms)
return atoms
def check_atoms(self):
"""Check that atoms objects are identical on all processors."""
if not mpi.compare_atoms(self.atoms, comm=self.wfs.world):
raise RuntimeError('Atoms objects on different processors ' +
'are not identical!')
def check_atoms(self):
"""Check that atoms objects are identical on all processors."""
if not mpi.compare_atoms(self.atoms, comm=self.wfs.world):
raise RuntimeError('Atoms objects on different processors ' +
'are not identical!')