Coverage for gpaw/test/response/test_na_plasmons_tetrahedron.py: 32%

1import pytest 

2from ase import Atoms 

3from gpaw.mpi import world 

4from gpaw import GPAW, PW 

5from gpaw.response.df import DielectricFunction 

6from gpaw.test import findpeak 

7 

8# Comparing the EELS spectrum of sodium for different block 

9# parallelizations. Intended to be run with 8 cores. 

10 

11pytestmark = pytest.mark.skipif(world.size < 4, reason='world.size < 4') 

12 

13 

14@pytest.mark.dielectricfunction 

15@pytest.mark.response 

16@pytest.mark.slow 

17@pytest.mark.xfail(reason='https://gitlab.com/gpaw/gpaw/-/jobs/5215834173') 

18def test_response_na_plasmons_tetrahedron(in_tmp_dir, scalapack): 

19 a = 4.23 / 2.0 

20 a1 = Atoms('Na', 

21 scaled_positions=[[0, 0, 0]], 

22 cell=(a, a, a), 

23 pbc=True) 

24 

25 a1.calc = GPAW(mode=PW(250), 

26 kpts={'size': (10, 10, 10), 'gamma': True}, 

27 parallel={'band': 1}, 

28 txt='small.txt') 

29 

30 a1.get_potential_energy() 

31 a1.calc.diagonalize_full_hamiltonian(nbands=20) 

32 a1.calc.write('gs_Na.gpw', 'all') 

33 

34 kwargs = {'integrationmode': 'tetrahedron integration', 

35 'ecut': 40} 

36 

37 # Calculate the dielectric functions: tetrahedral 1 block 

38 df1 = DielectricFunction('gs_Na.gpw', 

39 rate=0.001, 

40 nblocks=1, 

41 txt='1block.txt', 

42 **kwargs) 

43 df1NLFCx, df1LFCx = df1.get_dielectric_function(direction='x') 

44 

45 # tetrahedral 4 blocks 

46 df2 = DielectricFunction('gs_Na.gpw', 

47 rate=0.001, 

48 nblocks=4, 

49 txt='4block.txt', 

50 **kwargs) 

51 df2NLFCx, df2LFCx = df2.get_dielectric_function(direction='x') 

52 

53 # tetrahedron integration 4 blocks with large eta 

54 kwargs.update({'eta': 4.25}) 

55 df3 = DielectricFunction('gs_Na.gpw', 

56 rate=0.001, 

57 nblocks=4, 

58 txt='4block.txt', 

59 **kwargs) 

60 df3NLFCx, df3LFCx = df3.get_dielectric_function(direction='x') 

61 

62 # point integration 4 blocks with large eta (smearing) 

63 kwargs.update({'integrationmode': 'point integration', 'eta': 4.25}) 

64 df4 = DielectricFunction('gs_Na.gpw', 

65 rate=0.001, 

66 nblocks=4, 

67 txt='4block.txt', 

68 **kwargs) 

69 df4NLFCx, df4LFCx = df4.get_dielectric_function(direction='x') 

70 

71 # Compare plasmon frequencies and intensities 

72 w_w = df1.chi0calc.wd.omega_w 

73 

74 w1, I1 = findpeak(w_w, -(1. / df1LFCx).imag) 

75 w2, I2 = findpeak(w_w, -(1. / df2LFCx).imag) 

76 w3, I3 = findpeak(w_w, -(1. / df3LFCx).imag) 

77 w4, I4 = findpeak(w_w, -(1. / df4LFCx).imag) 

78 

79 # omegas don't change 

80 assert [w3, w4] == pytest.approx([0.283057, 0.300520], abs=1e-2) 

81 assert w1 == pytest.approx(w2, 1e-2) # omega: serial vs parallel 

82 # omega: PI & TI w/ large eta are aprx equal 

83 assert w4 == pytest.approx(w3, 2e-2, abs=True) 

84 assert I1 == pytest.approx(I2, 1e-3) # intensity: serial vs parallel