Coverage for /builds/kinetik161/ase/ase/lattice/triclinic.py: 95.92%

1"""Function-like object creating triclinic lattices. 

2 

3The following lattice creator is defined: 

4 Triclinic 

5""" 

6 

7import numpy as np 

8 

9from ase.data import reference_states as _refstate 

10from ase.lattice.bravais import Bravais 

11 

12 

13class TriclinicFactory(Bravais): 

14 "A factory for creating triclinic lattices." 

15 

16 # The name of the crystal structure in ChemicalElements 

17 xtal_name = "triclinic" 

18 

19 # The natural basis vectors of the crystal structure 

20 int_basis = np.array([[1, 0, 0], 

21 [0, 1, 0], 

22 [0, 0, 1]]) 

23 basis_factor = 1.0 

24 

25 # Converts the natural basis back to the crystallographic basis 

26 inverse_basis = np.array([[1, 0, 0], 

27 [0, 1, 0], 

28 [0, 0, 1]]) 

29 inverse_basis_factor = 1.0 

30 

31 def get_lattice_constant(self): 

32 """Get the lattice constant of an element with triclinic 

33 crystal structure.""" 

34 if _refstate[self.atomicnumber]['symmetry'] != self.xtal_name: 

35 raise ValueError(('Cannot guess the %s lattice constant of' 

36 + ' an element with crystal structure %s.') 

37 % (self.xtal_name, 

38 _refstate[self.atomicnumber]['symmetry'])) 

39 return _refstate[self.atomicnumber].copy() 

40 

41 def make_crystal_basis(self): 

42 """Make the basis matrix for the crystal unit cell and the system 

43 unit cell.""" 

44 lattice = self.latticeconstant 

45 if isinstance(lattice, type({})): 

46 a = lattice['a'] 

47 try: 

48 b = lattice['b'] 

49 except KeyError: 

50 b = a * lattice['b/a'] 

51 try: 

52 c = lattice['c'] 

53 except KeyError: 

54 c = a * lattice['c/a'] 

55 alpha = lattice['alpha'] 

56 beta = lattice['beta'] 

57 gamma = lattice['gamma'] 

58 else: 

59 if len(lattice) == 6: 

60 (a, b, c, alpha, beta, gamma) = lattice 

61 else: 

62 raise ValueError( 

63 "Improper lattice constants for triclinic crystal.") 

64 

65 degree = np.pi / 180.0 

66 cosa = np.cos(alpha * degree) 

67 cosb = np.cos(beta * degree) 

68 sinb = np.sin(beta * degree) 

69 cosg = np.cos(gamma * degree) 

70 sing = np.sin(gamma * degree) 

71 lattice = np.array( 

72 [[a, 0, 0], 

73 [b * cosg, b * sing, 0], 

74 [c * cosb, c * (cosa - cosb * cosg) / sing, 

75 c * np.sqrt(sinb**2 - ((cosa - cosb * cosg) / sing)**2)]]) 

76 self.latticeconstant = lattice 

77 self.miller_basis = lattice 

78 self.crystal_basis = (self.basis_factor * 

79 np.dot(self.int_basis, lattice)) 

80 self.basis = np.dot(self.directions, self.crystal_basis) 

81 assert abs(np.dot(lattice[0], lattice[1]) - a * b * cosg) < 1e-5 

82 assert abs(np.dot(lattice[0], lattice[2]) - a * c * cosb) < 1e-5 

83 assert abs(np.dot(lattice[1], lattice[2]) - b * c * cosa) < 1e-5 

84 assert abs(np.dot(lattice[0], lattice[0]) - a * a) < 1e-5 

85 assert abs(np.dot(lattice[1], lattice[1]) - b * b) < 1e-5 

86 assert abs(np.dot(lattice[2], lattice[2]) - c * c) < 1e-5 

87 

88 

89Triclinic = TriclinicFactory()