Ab initio structures and quartic force fields of phosphine oxide and phosphine sulphide

Riccardo Tarroni (1) , Manuele Lamarra (2)

1 Dipartimento di Chimica Fisica e Inorganica [Bologna]
2 UNIBO - Alma Mater Studiorum Università di Bologna = University of Bologna

Phosphine oxide, OPH3, and phosphine sulphide, SPH3 have been studied ab initio using various combinations of theoretical methods (MP2, CCSD, CCSD(T)) and basis sets (cc-pV(X+d)Z, cc-pCVZ, X=T,Q). For both molecules, high-level ab-initio full-quartic force fields have been calculated, and these have been used to predict the most important spectroscopic constants for several isotopologues. For OPH3, the semi-experimental equilibrium geometry and harmonic frequencies have been determined, by combining the theoretically calculated anharmonic corrections to the experimentally determined ground-state rotational constants and vibrational fundamentals. It is proved that, after applying anharmonic corrections, the unusually large disagreement between the experimental geometry and any high-level theoretical approach disappears.

Mots clés: Physical Sciences

Domaines: Matière Condensée [cond-mat]

Riccardo Tarroni, Manuele Lamarra. Ab initio structures and quartic force fields of phosphine oxide and phosphine sulphide. Molecular Physics, 2011, pp.1. ⟨10.1080/00268976.2011.601281⟩. ⟨hal-00721228⟩