def make_nacl_lattice(symbols, a):
assert len(symbols) == 2
cell = graingen.CubicUnitCell(a)
node_pos = graingen.fcc_nodes[:]
node_atoms = [
(symbols[0], 0.0, 0.0, 0.0),
(symbols[1], 0.5, 0.5, 0.5),
]
return make_lattice(cell, node_pos, node_atoms)
def make_zincblende_lattice(symbols, a):
assert len(symbols) == 2
cell = graingen.CubicUnitCell(a)
# nodes in unit cell (as fraction of unit cell parameters)
node_pos = graingen.fcc_nodes[:]
# atoms in node (as fraction of unit cell parameters)
node_atoms = [
(symbols[0], 0.0, 0.0, 0.0),
(symbols[1], 0.25, 0.25, 0.25),
]
return make_lattice(cell, node_pos, node_atoms)
def make_diamond_lattice(symbol, a):
cell = graingen.CubicUnitCell(a)
node_pos = get_diamond_node_pos()
node_atoms = [(symbol, 0.0, 0.0, 0.0)]
return make_lattice(cell, node_pos, node_atoms)
def make_bcc_lattice(symbol, a):
cell = graingen.CubicUnitCell(a)
node_pos = graingen.bcc_nodes[:]
node_atoms = [(symbol, 0.0, 0.0, 0.0)]
return make_lattice(cell, node_pos, node_atoms)
def make_simple_cubic_lattice(symbol, a):
cell = graingen.CubicUnitCell(a)
node = graingen.Node((0.0, 0.0, 0.0), [(symbol, 0.0, 0.0, 0.0)])
return graingen.CrystalLattice(cell, [node])