def main():
from bem import matter
# FCC
atoms = [
matter.Atom('Ni', (0, 0, 0)),
matter.Atom('Ni', (0.5, 0.5, 0)),
matter.Atom('Ni', (0.5, 0, 0.5)),
matter.Atom('Ni', (0, 0.5, 0.5))
]
# a=3.5238
a = 3.60 # this is inferred from the d-spacing values in the original fortran file
alpha = 90.
lattice = matter.Lattice(a=a,
b=a,
c=a,
alpha=alpha,
beta=alpha,
gamma=alpha)
fccNi = matter.Structure(atoms, lattice, sgid=225)
compute(
fccNi,
tex='xqg.tex',
N_RD=36,
N_HD=144,
out='int_samples.dat',
max_hkl_index=5,
)
return
interactive = False
import numpy as np
from bem import xscalc, diffraction, matter
atoms = [
matter.Atom('Ni', (0,0,0), occupancy=0.5), matter.Atom('Ni', (0.5, 0.5, 0), occupancy=0.5),
matter.Atom('Ni', (0.5,0,0.5), occupancy=0.5), matter.Atom('Ni', (0, 0.5, 0.5), occupancy=0.5),
matter.Atom('Cr', (0,0,0), occupancy=0.5), matter.Atom('Cr', (0.5, 0.5, 0), occupancy=0.5),
matter.Atom('Cr', (0.5,0,0.5), occupancy=0.5), matter.Atom('Cr', (0, 0.5, 0.5), occupancy=0.5),
]
a=3.5238
alpha = 90.
lattice = matter.Lattice(a=a, b=a, c=a, alpha=alpha, beta=alpha, gamma=alpha)
NiCr = matter.Structure(atoms, lattice, sgid=225)
def test():
lambdas = np.arange(0.05, 5.5, 0.001)
T = 300
calc = xscalc.XSCalculator(NiCr, T, max_diffraction_index=1)
assert np.isclose(calc.coh_xs, ((10.3+3.635)/2)**2*4*np.pi/100)
assert np.isclose(calc.inc_xs, 4*np.pi*((10.3**2+3.635**2)/2.-((10.3+3.635)/2.)**2)/100. + (5.2+1.83)/2)
return
def main():
global interactive
interactive = True
test()
return