Coverage for gpaw/test/elph/test_indices.py: 100%

1"""Unit test for elph/supercell and elph/gmatrix checking 

2whether they properly respect the self.indices. 

3 

4Note: If the users gives an index twice that's passed through, because that's 

5 how ase.phonons does it. 

6 

7""" 

8import numpy as np 

9import pytest 

10 

11from ase.build import bulk 

12# from ase.phonons import Phonons 

13from gpaw.elph import Supercell, ElectronPhononMatrix 

14# from gpaw.mpi import world 

15 

16 

17class FakeElectronPhononMatrix(ElectronPhononMatrix): 

18 def _set_supercell_cache(self, supercell_cache: str, 

19 load_sc_as_needed: bool): 

20 pass 

21 

22 def _read_phonon_cache(self): 

23 pass 

24 

25 

26def _supercell_all(atoms): 

27 natoms = len(atoms) 

28 sc = Supercell(atoms) 

29 assert len(sc.indices) == natoms 

30 assert sc.indices[0] == 0 

31 assert sc.indices[-1] == natoms - 1 

32 

33 

34def _gmatrix_all(atoms): 

35 natoms = len(atoms) 

36 fepm = FakeElectronPhononMatrix(atoms, None, {"name": "phonon"}) 

37 assert len(fepm.indices) == natoms 

38 assert fepm.indices[0] == 0 

39 assert fepm.indices[-1] == natoms - 1 

40 

41 

42def _supercell_indices(atoms, indices): 

43 natoms = len(atoms) 

44 nindices = len(indices) 

45 sci = Supercell(atoms, indices=indices) 

46 assert len(sci.indices) != natoms 

47 assert len(sci.indices) == nindices 

48 assert sci.indices[0] == indices[0] 

49 assert sci.indices[-1] == indices[-1] 

50 

51 

52def _gmatrix_indices(atoms, indices): 

53 natoms = len(atoms) 

54 nindices = len(indices) 

55 fepm = FakeElectronPhononMatrix(atoms, None, {"name": "phonon"}, 

56 indices=indices) 

57 assert len(fepm.indices) != natoms 

58 assert len(fepm.indices) == nindices 

59 assert fepm.indices[0] == indices[0] 

60 assert fepm.indices[-1] == indices[-1] 

61 

62 

63@pytest.mark.elph 

64def test_indices(): 

65 

66 # arbitrary atoms object 

67 n = 3 

68 atoms = bulk('Li', crystalstructure='bcc', a=3.51, cubic=True) * (n, n, n) 

69 assert len(atoms) == 2 * n**3 

70 

71 # case 1: self.indices not given 

72 _supercell_all(atoms) 

73 _gmatrix_all(atoms) 

74 

75 # TODO: Supercell.calculate_gradient()? Would need fake cache. 

76 # TODO: Supercell.calculate_supercell_matrix()? Would need fake cache and 

77 # stuff. 

78 

79 # case 2: gives some random indices 

80 seed = 123456 

81 rng = np.random.default_rng(seed) 

82 indices = rng.integers(0, len(atoms), 

83 rng.integers(0, len(atoms) - 1)) 

84 _supercell_indices(atoms, indices) 

85 _gmatrix_indices(atoms, indices) 

86 # TODO: Supercell.calculate_gradient()? Would need fake cache. 

87 # TODO: Supercell.calculate_supercell_matrix()? Would need fake cache 

88 # and stuff.