1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
import pytest
import numpy as np
from ase import Atoms
@pytest.fixture
def dimer_params():
dimer_params = {}
a = 2.0
dimer_params["symbols"] = "Ni" * 2
dimer_params["positions"] = [(0, 0, 0), (a, 0, 0)]
dimer_params["cell"] = (1000 * a, 1000 * a, 1000 * a)
dimer_params["pbc"] = (False, False, False)
return dimer_params
@pytest.mark.calculator_lite
@pytest.mark.calculator("lammpslib")
def test_lammpslib_small_nonperiodic(factory, dimer_params, calc_params_NiH):
"""Test that lammpslib handle nonperiodic cases where the cell size
in some directions is small (for example for a dimer)"""
# Make a dimer in a nonperiodic box
dimer = Atoms(**dimer_params)
# Set of calculator
calc = factory.calc(**calc_params_NiH)
dimer.calc = calc
# Check energy
energy_ref = -1.10756669119
energy = dimer.get_potential_energy()
print("Computed energy: {}".format(energy))
assert energy == pytest.approx(energy_ref, rel=1e-4)
# Check forces
forces_ref = np.array(
[[-0.9420162329811532, 0.0, 0.0], [+0.9420162329811532, 0.0, 0.0]]
)
forces = dimer.get_forces()
print("Computed forces:")
print(np.array2string(forces))
assert forces == pytest.approx(forces_ref, rel=1e-4)
|
