def test_multipole_derivative(self):
Rab = 2.0 * np.random.random(3) + 1
for k in range(6):
ll = 1 # derivative
n_comps_symm = multipole_components(k)
M = np.random.random(n_comps_symm)
# unfold the tensor
M_full = symmetry.unfold_tensor(M, k)
sym_indices = symmetry.get_symm_indices(k)
np.testing.assert_allclose(M, M_full.take(sym_indices))
res = multipole_derivative(k, ll, Rab, M, 0.0)
ref_field = polfields.field(Rab, k, M_full, ll)
np.testing.assert_allclose(ref_field, res, atol=1e-14)
if k <= 2:
damp = 2.0
a_i = 4.0
a_j = 10.0
a = 1 / (a_i * a_j)**(1 / 6) * damp
res = multipole_derivative(k, ll, Rab, M, a)
ref_field = polfields.thole_exp_field(Rab, k, M_full, ll, a)
np.testing.assert_allclose(ref_field, res, atol=1e-14)
def test_multipole_components(self):
for k in range(6):
comps = (k + 1) * (k + 2) / 2
assert comps == multipole_components(k)