except ImportError:
pass
else:
w += ['png', 'eps']
for format in w:
print(format, 'O', end=' ')
fname1 = 'io-test.1.' + format
fname2 = 'io-test.2.' + format
write(fname1, atoms, format=format)
if format not in ['cube', 'png', 'eps', 'cfg', 'struct']:
write(fname2, images, format=format)
if format in r:
print('I')
a1 = read(fname1)
assert np.all(
np.abs(a1.get_positions() - atoms.get_positions()) < 1e-6)
if format in ['traj', 'cube', 'cfg', 'struct']:
assert np.all(np.abs(a1.get_cell() - atoms.get_cell()) < 1e-6)
if format in ['cfg']:
assert np.all(
np.abs(a1.get_array('extra') -
atoms.get_array('extra')) < 1e-6)
if format not in ['cube', 'png', 'eps', 'cfg', 'struct']:
a2 = read(fname2)
a3 = read(fname2, index=0)
a4 = read(fname2, index=slice(None))
else:
print()
def read_vasp(filename='CONTCAR'):
"""Import POSCAR/CONTCAR type file.
Reads unitcell, atom positions and constraints from the POSCAR/CONTCAR
file and tries to read atom types from POSCAR/CONTCAR header, if this fails
the atom types are read from OUTCAR or POTCAR file.
"""
from ase_ext import Atoms, Atom
from ase_ext.constraints import FixAtoms, FixScaled
from ase_ext.data import chemical_symbols
import numpy as np
if isinstance(filename, str):
f = open(filename)
else: # Assume it's a file-like object
f = filename
# First line should contain the atom symbols , eg. "Ag Ge" in
# the same order
# as later in the file (and POTCAR for the full vasp run)
atomtypes = f.readline().split()
lattice_constant = float(f.readline())
# Now the lattice vectors
a = []
for ii in range(3):
s = f.readline().split()
floatvect = float(s[0]), float(s[1]), float(s[2])
a.append(floatvect)
basis_vectors = np.array(a) * lattice_constant
# Number of atoms. Again this must be in the same order as
# in the first line
# or in the POTCAR or OUTCAR file
atom_symbols = []
numofatoms = f.readline().split()
#vasp5.1 has an additional line which gives the atom types
#the following try statement skips this line
try:
int(numofatoms[0])
except ValueError:
numofatoms = f.readline().split()
numsyms = len(numofatoms)
if len(atomtypes) < numsyms:
# First line in POSCAR/CONTCAR didn't contain enough symbols.
atomtypes = atomtypes_outpot(f.name, numsyms)
else:
try:
for atype in atomtypes[:numsyms]:
if not atype in chemical_symbols:
raise KeyError
except KeyError:
atomtypes = atomtypes_outpot(f.name, numsyms)
for i, num in enumerate(numofatoms):
numofatoms[i] = int(num)
[atom_symbols.append(atomtypes[i]) for na in range(numofatoms[i])]
# Check if Selective dynamics is switched on
sdyn = f.readline()
selective_dynamics = sdyn[0].lower() == "s"
# Check if atom coordinates are cartesian or direct
if selective_dynamics:
ac_type = f.readline()
else:
ac_type = sdyn
cartesian = ac_type[0].lower() == "c" or ac_type[0].lower() == "k"
tot_natoms = sum(numofatoms)
atoms_pos = np.empty((tot_natoms, 3))
if selective_dynamics:
selective_flags = np.empty((tot_natoms, 3), dtype=bool)
for atom in range(tot_natoms):
ac = f.readline().split()
atoms_pos[atom] = (float(ac[0]), float(ac[1]), float(ac[2]))
if selective_dynamics:
curflag = []
for flag in ac[3:6]:
curflag.append(flag == 'F')
selective_flags[atom] = curflag
# Done with all reading
if type(filename) == str:
f.close()
if cartesian:
atoms_pos *= lattice_constant
atoms = Atoms(symbols=atom_symbols, cell=basis_vectors, pbc=True)
if cartesian:
atoms.set_positions(atoms_pos)
else:
atoms.set_scaled_positions(atoms_pos)
if selective_dynamics:
constraints = []
indices = []
for ind, sflags in enumerate(selective_flags):
if sflags.any() and not sflags.all():
constraints.append(FixScaled(atoms.get_cell(), ind, sflags))
elif sflags.all():
indices.append(ind)
if indices:
constraints.append(FixAtoms(indices))
if constraints:
atoms.set_constraint(constraints)
return atoms
import numpy as np
from ase_ext.calculators.emt import EMT
from ase_ext import Atoms
a = 3.60
b = a / 2
cu = Atoms('Cu',
positions=[(0, 0, 0)],
cell=[(0, b, b), (b, 0, b), (b, b, 0)],
pbc=1,
calculator=EMT())
e0 = cu.get_potential_energy()
print(e0)
cu.set_cell(cu.get_cell() * 1.001, scale_atoms=True)
e1 = cu.get_potential_energy()
V = a**3 / 4
B = 2 * (e1 - e0) / 0.003**2 / V * 160.2
print(B)
for i in range(4):
x = 0.001 * i
A = np.array([(x, b, b + x), (b, 0, b), (b, b, 0)])
cu.set_cell(A, scale_atoms=True)
e = cu.get_potential_energy() - e0
if i == 0:
print(i, e)
else:
print(i, e, e / x**2)
A = np.array([(0, b, b), (b, 0, b), (6 * b, 6 * b, 0)])
from ase_ext.io import write, PickleTrajectory
from ase_ext.calculators.emt import ASAP
# Distance between Cu atoms on a (100) surface:
d = 2.74
h1 = d * sqrt(3) / 2
h2 = d * sqrt(2.0 / 3)
initial = Atoms(
symbols='Pt',
positions=[
(0, 0, 0)
], #(1.37,0.79,2.24),(2.74,1.58,4.48),(0,0,6.72),(1.37,0.79,8.96),(2.74,1.58,11.2)],
cell=([(d, 0, 0), (d / 2, h1, 0), (d / 2, h1 / 3, -h2)]),
pbc=(True, True, True))
initial *= (7, 8, 6) # 5x5 (100) surface-cell
cell = initial.get_cell()
cell[2] = (0, 0, 22)
initial.set_cell(cell)
#initial.set_pbc((True,True,False))
# Approximate height of Ag atom on Cu(100) surfece:
h0 = 2.2373
initial += Atom('Pt', (10.96, 11.074, h0))
initial += Atom('Pt', (13.7, 11.074, h0))
initial += Atom('Pt', (9.59, 8.701, h0))
initial += Atom('Pt', (12.33, 8.701, h0))
initial += Atom('Pt', (15.07, 8.701, h0))
initial += Atom('Pt', (10.96, 6.328, h0))
initial += Atom('Pt', (13.7, 6.328, h0))
if 0:
view(initial)