Coverage for gpaw/test/cdft/test_cdft_fd_forces.py: 100%

1import numpy as np 

2import pytest 

3from ase import Atoms 

4 

5from gpaw import GPAW, Mixer 

6from gpaw.cdft.cdft import CDFT 

7 

8 

9@pytest.mark.old_gpaw_only 

10def test_cdft_fd_forces(in_tmp_dir): 

11 

12 sys = Atoms('N2', positions=([0., 0., 0.], [0., 0., 1])) 

13 sys.center(3) 

14 sys.set_pbc(False) 

15 sys.set_initial_magnetic_moments([0.5, 0.5]) 

16 

17 calc_b = GPAW(h=0.2, 

18 basis='dzp', 

19 charge=1, 

20 mode='lcao', 

21 xc='PBE', 

22 spinpol=True, 

23 mixer=Mixer(beta=0.25, nmaxold=3, weight=100.0), 

24 txt='N2.txt', 

25 convergence={'eigenstates': 1.0e-2, 'density': 1.0e-2, 

26 'energy': 1e-2}) 

27 

28 sys.calc = calc_b 

29 sys.get_potential_energy() 

30 

31 cdft_b = CDFT(calc=calc_b, 

32 atoms=sys, 

33 charge_regions=[[0]], 

34 charges=[1], 

35 charge_coefs=[22], 

36 forces='fd', 

37 method='L-BFGS-B', 

38 txt='N2.cdft', 

39 minimizer_options={'gtol': 0.1}) 

40 

41 sys.calc = cdft_b 

42 sys.get_potential_energy() 

43 f = sys.get_forces() 

44 # check that forces in x and y directions are small 

45 for i in [0, 1]: 

46 assert (np.isclose(f[0, i], 0.)) 

47 assert (np.isclose(f[1, i], 0.))