Coverage for gpaw/test/test_rattle.py: 100%

1import numpy as np 

2from ase.calculators.tip3p import TIP3P, rOH, angleHOH 

3from ase.optimize import FIRE 

4from ase.constraints import FixBondLengths 

5from gpaw.utilities.watermodel import FixBondLengthsWaterModel 

6from gpaw.utilities.watermodel import TIP3PWaterModel as TIP3Pc 

7from ase.data import s22 

8 

9# check that all combinations of watermodel implementations 

10# and constraints give the same results 

11 

12 

13def test_rattle(in_tmp_dir): 

14 pairs = [(3 * i + j, 3 * i + (j + 1) % 3) 

15 for i in range(2) 

16 for j in [0, 1, 2]] 

17 

18 ct = 0 

19 distances = np.zeros(4) 

20 for calc in [TIP3P(), TIP3Pc()]: 

21 for fix in [FixBondLengths, FixBondLengthsWaterModel]: 

22 atoms = s22.create_s22_system('Water_dimer') 

23 

24 for m in [0, 3]: 

25 atoms.set_angle(m + 1, m, m + 2, angleHOH) 

26 atoms.set_distance(m, m + 1, rOH, fix=0) 

27 atoms.set_distance(m, m + 2, rOH, fix=0) 

28 atoms.set_angle(m + 1, m, m + 2, angleHOH) 

29 

30 atoms.set_constraint(fix(pairs)) 

31 

32 atoms.calc = calc 

33 

34 with FIRE(atoms, logfile='test.log') as opt: 

35 opt.run(0.05) 

36 p = atoms.get_positions() 

37 d = np.linalg.norm(p[0] - p[3]) 

38 distances[ct] = d 

39 ct += 1 

40 

41 assert (np.diff(distances) < 1e-6).all()