def test_write_dftb_velocities():
atoms = Atoms('H2')
velocities = np.linspace(-1, 2, num=6).reshape(2, 3)
atoms.set_velocities(velocities)
write_dftb_velocities(atoms, filename='velocities.txt')
velocities = np.loadtxt('velocities.txt') * Bohr / AUT
assert np.allclose(velocities, atoms.get_velocities())
def test_read_dftb_velocities():
atoms = Atoms('H2')
filename = 'geo_end.xyz'
with open(filename, 'w') as fd:
fd.write(geo_end_xyz)
# Velocities (in Angstrom / ps) of the last MD iteration
# The first 4 columns are the atom charge and coordinates
read_dftb_velocities(atoms, filename=filename)
velocities = np.linspace(-1, 2, num=6).reshape(2, 3)
velocities /= 1e-12 * second
assert np.allclose(velocities, atoms.get_velocities())