Relativistic molecular orbital study of the optical and magnetic properties of hexachloro protactinate (IV):PaCl_6~(2-)

摘要

Our ab initio all-electron Dirac-Fock and the corresponding nonrelativistic limit calculations performed at four Pa-Cl bond distances yield for octahedral PaCl_6~(2-) the optimized Pa-Cl bond distances of 2.758 and 2.771 A,respectively.Dirac scattered wave and its nonrelativistic limit calculations are performed at the optimized Pa-Cl bond distances using a first-order perturbation procedure to obtain the molecular g and hyperfine tensors for the octahedral anion PaCl_6~(2-).The calculated Zeeman and ~(231)Pa hyperfine interactions are in fairly good agreement with the electron paramagnetic resonance and electron nuclear double resonance values of the Pa~(4+) impurity site in the octahedral Cs_2ZrCl_6 lattice.The calculated relativistic transition energies of the 5f-> 5f and 5f->6d absorption bands are also in good agreement with the experimental results.