ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Force constants have been obtained for PF5 from ab initio SCF calculations, using a basis set of double zeta plus polarization quality for phosphorus, and nearly triple zeta for fluorine. Parallel calculations have been performed for SiF4, PF3, and SF6, to obtain optimum scale factors for PF5. SCF scale factors are different for stretching and bending motions, and also for interaction constants. Scale factors for SiF4 and SF6 differ substantially; intermediate values seem appropriate for PF5. The scaled ab initio force field for PF5 predicts all available spectroscopic data satisfactorily, with an average discrepancy of only 1.2 times the estimated uncertainty. A refined force field has been obtained by least-squares fitting, constraining three of the off-diagonal force constants. The normal modes of PF5 are described, with particular emphasis on the E' bending motion and pseudorotation. Trends in force constants of SiF4, PF3, PF5, and SF6 are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.453448
