One-Electron Reduced Density Matrices forLi(P2)andB(P2)

Abstract
The one-electron reduced density matrix (one-matrix) is reported for the Weiss Li(P2) configuration interaction (CI) wave function and for the B(P2) polarization, first-order, and 187-term CI functions of Schaefer, Harris, and Klemm. The one-matrix of the Li(P2) function demonstrated none of the symmetry mixing expected of a P2 state due to the "S2-type" restrictions imposed on the wave function. Both the 187-term and first-order wave functions for B(P2) do not fully describe the hyperfine structure because the 187-term function lacks an adequate basis and the first-order function systematically excludes some important radial-type correlation terms in the L shell. By including a few such terms, this function could represent an effective systematic approach to hyperfine-structure determinations. The polarization function excludes too many important terms to be reliable. These studies indicate that the polarization to the 1s and 2s orbitals decreased with the inclusion of more correlation in the wave function and that the inclusion of the 2s2p near-degeneracy effect did materially influence the forms of the dominant natural spin orbitals. Pertinent suggestions are presented for constructing improved CI wave functions for B(P2).