Coverage for gpaw/test/new/test_tb_mode.py: 100%

1import pytest 

2from ase import Atoms 

3from ase.optimize import BFGS 

4from gpaw.new.ase_interface import GPAW 

5from gpaw.test.xc.test_qna_stress import numeric_stress 

6 

7 

8@pytest.mark.serial 

9def test_tb_mode_molecule(): 

10 atoms = Atoms('LiH', 

11 [[0, 0.1, 0.2], 

12 [0, 0, 1.4]]) 

13 atoms.calc = GPAW( 

14 mode='tb', 

15 symmetry='off', # ??? should not be needed 

16 txt='-') # None) 

17 atoms.get_potential_energy() 

18 # f1 = atoms.get_forces() 

19 # f2 = calculate_numerical_forces(atoms) 

20 # assert abs(f1 - f2).max() < 0.0005 

21 

22 

23@pytest.mark.serial 

24def test_tb_mode_bulk(): 

25 a = 2.0 

26 atoms = Atoms('Li', 

27 cell=[a, a, a], 

28 pbc=True) 

29 atoms.calc = GPAW( 

30 mode='tb', 

31 kpts=(2, 2, 2)) 

32 atoms.get_potential_energy() 

33 return 

34 from ase.filters import ExpCellFilter 

35 f = atoms.get_forces() 

36 assert abs(f).max() < 0.0001 

37 e = atoms.get_potential_energy() 

38 s = atoms.get_stress() 

39 print(a, e, s) 

40 s2 = [numeric_stress(atoms, 1e-6, component) 

41 for component in [(0, 0), (1, 1), (2, 2), (1, 2), (0, 2), (0, 1)]] 

42 print(s2) 

43 assert abs(s - s2).max() < 0.0001 

44 BFGS(ExpCellFilter(atoms)).run(fmax=0.002) 

45 s = atoms.get_stress() 

46 print(s) 

47 assert abs(s).max() < 0.0001 

48 assert atoms.cell[0, 0] == pytest.approx(2.044, abs=0.0005)