THEORETICAL-STUDIES OF THE STRUCTURES AND ELECTRONIC-PROPERTIES OF U(NH2)(3) AND NP(NH2)(3)

The electronic structure of the model compounds U(NH2)(3) and Np(NH2)( 3) is investigated with the aid of ab initio electronic structure tech niques. The electronic ground states and equilibrium geometries of the se complexes are determined using multiconfiguration SCF techniques. T he ground state and low-lying excited states of U(NH2)(3) are found to arise from the (5f)(2) (6d)(1) and (5f)(3) configurations on the meta l. The lowest state of the (5f)(2) (6d)(1) and (Sf)(3) configurations are comparable in energy. NP(NH2)(3) utilizes the (5f)(4) configuratio n, with the (5f)(3) (6d)(1) configuration lying about 2 eV higher in e nergy. Comparisons are made to the AnL(3) counterparts with L=CH3.