Line data    Source code

       1             : # SPDX-FileCopyrightText: 2025 PairInteraction Developers
       2             : # SPDX-License-Identifier: LGPL-3.0-or-later
       3             : 
       4             : 
       5           1 : import numpy as np
       6           1 : import pairinteraction.real as pi
       7           1 : import pytest
       8           1 : from pairinteraction import perturbative
       9           1 : from pairinteraction.units import ureg
      10             : 
      11             : 
      12           1 : @pytest.fixture
      13           1 : def system_pair_sample() -> pi.SystemPair:
      14           1 :     basis = pi.BasisAtom(
      15             :         species="Rb",
      16             :         n=(59, 63),
      17             :         l=(0, 1),
      18             :         m=(-1.5, 1.5),
      19             :     )
      20           1 :     system = pi.SystemAtom(basis=basis)
      21           1 :     system.set_diamagnetism_enabled(False)
      22           1 :     system.set_magnetic_field([0, 0, 1e-3], "gauss")
      23           1 :     if not system.is_diagonal:
      24           1 :         pi.diagonalize([system], diagonalizer="eigen", sort_by_energy=False)
      25           1 :     basis_pair = pi.BasisPair([system, system])
      26           1 :     system_pair = pi.SystemPair(basis_pair)
      27           1 :     theta = 0
      28           1 :     r = 12
      29           1 :     system_pair.set_distance_vector(r * np.array([np.sin(theta), 0, np.cos(theta)]), "micrometer")
      30           1 :     system_pair.set_interaction_order(3)
      31           1 :     return system_pair
      32             : 
      33             : 
      34           1 : @pytest.mark.filterwarnings("ignore::DeprecationWarning")
      35           1 : def test_c3_with_system(system_pair_sample: pi.SystemPair) -> None:
      36             :     """Test whether the C3 coefficient with a given system is calculated correctly."""
      37           1 :     ket_tuple_list = [
      38             :         (pi.KetAtom("Rb", n=61, l=0, j=0.5, m=0.5), pi.KetAtom("Rb", n=61, l=1, j=1.5, m=0.5)),
      39             :         (pi.KetAtom("Rb", n=61, l=1, j=1.5, m=0.5), pi.KetAtom("Rb", n=61, l=0, j=0.5, m=0.5)),
      40             :     ]
      41           1 :     c3 = perturbative.get_c3_from_system(
      42             :         system_pair=system_pair_sample, ket_tuple_list=ket_tuple_list, unit="planck_constant * gigahertz * micrometer^3"
      43             :     )
      44           1 :     assert np.isclose(-0.5 * c3, 3.1515)
      45             : 
      46             : 
      47           1 : @pytest.mark.filterwarnings("ignore::DeprecationWarning")
      48           1 : def test_c3_create_system() -> None:
      49             :     """Test whether the C3 coefficient with automatically constructed system is calculated correctly."""
      50           1 :     ket_tuple_list = [
      51             :         (pi.KetAtom("Rb", n=61, l=0, j=0.5, m=0.5), pi.KetAtom("Rb", n=61, l=1, j=1.5, m=0.5)),
      52             :         (pi.KetAtom("Rb", n=61, l=1, j=1.5, m=0.5), pi.KetAtom("Rb", n=61, l=0, j=0.5, m=0.5)),
      53             :     ]
      54           1 :     magnetic_field = ureg.Quantity([0, 0, 10], "gauss")
      55           1 :     electric_field = ureg.Quantity([0, 0, 0], "volt/cm")
      56           1 :     distance_vector = ureg.Quantity([0, 0, 500], "micrometer")
      57             : 
      58           1 :     system = perturbative.create_system_for_perturbative(
      59             :         ket_tuple_list, electric_field, magnetic_field, distance_vector
      60             :     )
      61             : 
      62           1 :     c3 = perturbative.get_c3_from_system(
      63             :         system_pair=system, ket_tuple_list=ket_tuple_list, unit="planck_constant * gigahertz * micrometer^3"
      64             :     )
      65           1 :     assert np.isclose(-0.5 * c3, 3.2188)
      66             : 
      67             : 
      68           1 : @pytest.mark.filterwarnings("ignore::DeprecationWarning")
      69           1 : def test_c6_with_system(system_pair_sample: pi.SystemPair) -> None:
      70             :     """Test whether the C6 coefficient with a given system is calculated correctly."""
      71           1 :     ket_atom = pi.KetAtom(species="Rb", n=61, l=0, j=0.5, m=0.5)
      72           1 :     c6 = perturbative.get_c6_from_system(
      73             :         ket_tuple=(ket_atom, ket_atom),
      74             :         system_pair=system_pair_sample,
      75             :         unit="planck_constant * gigahertz * micrometer^6",
      76             :     )
      77           1 :     assert np.isclose(c6, 167.880)
      78             : 
      79             : 
      80           1 : @pytest.mark.filterwarnings("ignore::DeprecationWarning")
      81           1 : def test_c6_create_system() -> None:
      82             :     """Test whether the C6 coefficient with automatically constructed system is calculated correctly."""
      83           1 :     magnetic_field = ureg.Quantity([0, 0, 10], "gauss")
      84           1 :     electric_field = ureg.Quantity([0, 0, 0], "volt/cm")
      85           1 :     distance_vector = ureg.Quantity([0, 0, 500], "micrometer")
      86           1 :     ket_atom = pi.KetAtom(species="Rb", n=61, l=0, j=0.5, m=0.5)
      87             : 
      88           1 :     system = perturbative.create_system_for_perturbative(
      89             :         [(ket_atom, ket_atom)], electric_field, magnetic_field, distance_vector
      90             :     )
      91             : 
      92           1 :     c6 = perturbative.get_c6_from_system(
      93             :         ket_tuple=(ket_atom, ket_atom), system_pair=system, unit="planck_constant * gigahertz * micrometer^6"
      94             :     )
      95           1 :     assert np.isclose(c6, 169.149)