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"""Module for building atomic structures"""
from ase import Atom, Atoms
def bcc100(symbol, a, layers, L):
"""Build a bcc(100) surface
symbol: chemical symbol ('H', 'Li', ...)
a : lattice constant
layers: number of layers
L : height of unit cell"""
a = float(a)
# Distance between layers:
z = a / 2
assert L > layers * z, 'Unit cell too small!'
# Start with an empty Atoms object with an orthorhombic unit cell:
atoms = Atoms(pbc=(True, True, False), cell=(a, a, L))
# Fill in the atoms:
for n in range(layers):
position = [a / 2 * (n % 2), a / 2 * (n % 2), n * z]
atoms.append(Atom(symbol, position))
atoms.center(axis=2)
return atoms
if __name__ == '__main__':
bcc = bcc100('Al', 4.0, 4, 15.0)
from ase.visualize import view
view(bcc * (4, 4, 2))
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