Young Sir Chung

Geometries and bond energies of PHn and PHn+ (n=1–3)

All‐electron complete active space self‐consistent field (CASSCF) followed by full second‐order configuration interaction (SOCI) calculations which included up to 1.7 million configurations have been made on several electronic states of PHn and PHn+ (n=1–3). A comparison is made of the results of several basis sets up to the largest set, namely, the (13s10p3d2u2009f1g/7s6p3d2u2009f1g) basis set for P and a (10s5p1d/8s4p1d) basis set for the hydrogen atom. Relativistic effective core potentials/CASSCF/multireference configuration interaction computations have also been carried out. The properties of three new excited states for PH3 have been computed as well as the experimentally observed Xu20091A1, 3A’2, and 1A’2 states. The calculated inversion barrier of PH3 is 34.6 kcal/mol whereas the corresponding inversion barrier of PH3+ is only 2.5 kcal/mol. The bond energies of PHn and PHn+ as well as adiabatic ionization energies of PHn are computed and compared with experimental results. The core‐valence and core‐external ...