def METHOD_NAME(self):
    # tests the AGF2 ionization potentials for H2O/cc-pvdz
    e_ip, v_ip = self.gf2.ipagf2(nroots=3)
    v_ip = [np.linalg.norm(v)**2 for v in v_ip]
    self.assertAlmostEqual(e_ip[0], 0.45080222600137465, 6)
    self.assertAlmostEqual(e_ip[1], 0.5543195106668687 , 6)
    self.assertAlmostEqual(e_ip[2], 0.6299640547362962 , 6)
    self.assertAlmostEqual(v_ip[0], 0.9704061235804103 , 6)
    self.assertAlmostEqual(v_ip[1], 0.9702372037466642 , 6)
    self.assertAlmostEqual(v_ip[2], 0.9713854565834782 , 6)