def test_crystal_diffraction(self):
crystals_list = xraylib.Crystal_GetCrystalsList()
self.assertEqual(len(crystals_list), 38)
for crystal_name in crystals_list:
cs = xraylib.Crystal_GetCrystal(crystal_name)
self.assertEqual(crystal_name, cs['name'])
with self.assertRaises(ValueError):
cs = xraylib.Crystal_GetCrystal(None)
with self.assertRaises(ValueError):
cs = xraylib.Crystal_GetCrystal("non-existent-crystal")
cs = xraylib.Crystal_GetCrystal("Diamond")
cs_copy = xraylib.Crystal_MakeCopy(cs)
with self.assertRaises(ValueError):
xraylib.Crystal_AddCrystal(cs)
with self.assertRaises(ValueError):
xraylib.Crystal_AddCrystal(cs_copy)
cs_copy['name'] = "Diamond-copy"
xraylib.Crystal_AddCrystal(cs_copy)
cs_copy['name'] = 20012016
with self.assertRaises(TypeError):
xraylib.Crystal_AddCrystal(cs_copy)
cs_copy['name'] = "Diamond-copy"
cs_copy['atom'] = list()
with self.assertRaises(TypeError):
xraylib.Crystal_AddCrystal(cs_copy)
cs_copy['atom'] = (25, "jkewjfpwejffj", None, )
with self.assertRaises(TypeError):
xraylib.Crystal_AddCrystal(cs_copy)
del cs_copy['atom']
with self.assertRaises(KeyError):
xraylib.Crystal_AddCrystal(cs_copy)
crystals_list = xraylib.Crystal_GetCrystalsList()
self.assertEqual(len(crystals_list), 39)
for crystal_name in crystals_list:
cs = xraylib.Crystal_GetCrystal(crystal_name)
self.assertEqual(crystal_name, cs['name'])
current_ncrystals = len(crystals_list)
for i in range(xraylib.CRYSTALARRAY_MAX):
cs_copy = xraylib.Crystal_MakeCopy(cs)
cs_copy['name'] = "Diamond copy {}".format(i)
if current_ncrystals < xraylib.CRYSTALARRAY_MAX:
xraylib.Crystal_AddCrystal(cs_copy)
current_ncrystals = current_ncrystals + 1
self.assertEqual(len(xraylib.Crystal_GetCrystalsList()), current_ncrystals)
else:
with self.assertRaises(RuntimeError):
xraylib.Crystal_AddCrystal(cs_copy)
self.assertEqual(len(xraylib.Crystal_GetCrystalsList()), xraylib.CRYSTALARRAY_MAX)
cs = xraylib.Crystal_GetCrystal("Diamond")
# Bragg angle
angle = xraylib.Bragg_angle(cs, 10.0, 1, 1, 1)
self.assertAlmostEqual(angle, 0.3057795845795849)
with self.assertRaises(TypeError):
angle = xraylib.Bragg_angle(None, 10.0, 1, 1, 1)
with self.assertRaises(ValueError):
angle = xraylib.Bragg_angle(cs, -10.0, 1, 1, 1)
with self.assertRaises(TypeError):
angle = xraylib.Bragg_angle(cs, 1, 1, 1)
# Q_scattering_amplitude
tmp = xraylib.Q_scattering_amplitude(cs, 10.0, 1, 1, 1, math.pi/4.0)
self.assertAlmostEqual(tmp, 0.19184445408324474)
tmp = xraylib.Q_scattering_amplitude(cs, 10.0, 0, 0, 0, math.pi/4.0)
self.assertEqual(tmp, 0.0)
# Atomic factors
(f0, f_prime, f_prime2) = xraylib.Atomic_Factors(26, 10.0, 1.0, 10.0)
self.assertAlmostEqual(f0, 65.15)
self.assertAlmostEqual(f_prime, -0.22193271025027966)
self.assertAlmostEqual(f_prime2, 22.420270655080493)
with self.assertRaises(ValueError):
(f0, f_prime, f_prime2) = xraylib.Atomic_Factors(-10, 10.0, 1.0, 10.0)
# unit cell volume
tmp = xraylib.Crystal_UnitCellVolume(cs)
self.assertAlmostEqual(tmp, 45.376673902751)
# crystal dspacing
tmp = xraylib.Crystal_dSpacing(cs, 1, 1, 1)
self.assertAlmostEqual(tmp, 2.0592870875248344)
del cs
atom['y'], atom['z']))
print("")
print("Si111 at 8 KeV. Incidence at the Bragg angle:")
energy = 8
debye_temp_factor = 1.0
rel_angle = 1.0
bragg = xraylib.Bragg_angle(cryst, energy, 1, 1, 1)
print(" Bragg angle: Rad: {} Deg: {}".format(bragg, bragg * 180 / math.pi))
q = xraylib.Q_scattering_amplitude(cryst, energy, 1, 1, 1, rel_angle)
print(" Q Scattering amplitude: {}".format(q))
#notice the 3 return values!!!
f0, fp, fpp = xraylib.Atomic_Factors(14, energy, q, debye_temp_factor)
print(" Atomic factors (Z = 14) f0, fp, fpp: {}, {}, i*{}".format(
f0, fp, fpp))
FH = xraylib.Crystal_F_H_StructureFactor(cryst, energy, 1, 1, 1,
debye_temp_factor, rel_angle)
print(" FH(1,1,1) structure factor: ({}, {})".format(FH.real, FH.imag))
F0 = xraylib.Crystal_F_H_StructureFactor(cryst, energy, 0, 0, 0,
debye_temp_factor, rel_angle)
print(" F0=FH(0,0,0) structure factor: ({}, {})".format(F0.real, F0.imag))
# Diamond diffraction parameters
cryst = xraylib.Crystal_GetCrystal("Diamond")
if cryst is None:
raise KeyError('Diamond crystal not found')