Moving complex quad file to comlpex integrate

tests/dielectric/test_lindhard_dielectric.py

@@ -22,3 +22,25 @@ def test_lindhard_dielectric(test_input, expected):
 		eps_to_test(test_input), expected,
 		decimal=6, err_msg='b function is off'
 	)
+
+
+@pytest.mark.parametrize("test_input,expected", [
+	((100, 100), -883.3001542404703 + 1.2566370613549341e8j),
+	((100, 1e5), 5.827225842825694e7 + 3.933446612656656e7j),
+	((100, 1e10), 1.0084823001646925 + 2.0013975538629039e-10j),
+	((100, 1e7), 8483.300121667038 + 0.6340397839154446)
+])
+def test_zeta_pi_lindhard_dielectric(zeta_p_i_epsilon, test_input, expected):
+	u, y = test_input
+	actual = zeta_p_i_epsilon(np.sqrt(u**2 + y**2))
+
+	np.testing.assert_allclose(
+		actual, expected,
+		rtol=10**3.8, err_msg='lindhard dielectric differs from Mathematica'
+	)
+
+
+@pytest.fixture
+def zeta_p_i_epsilon():
+	params = CalculationParams(omega=1e9, omega_p=3.544907701811032e15, tau=1e-14, v_f=2e6)
+	return pynam.dielectric.get_lindhard_dielectric(params)