Release Time:2019-03-10  Hits:

Indexed by: Journal Article

Date of Publication: 2008-08-01

Journal: MOLECULAR PHYSICS

Included Journals: Scopus、EI、SCIE

Volume: 106

Issue: 15

Page Number: 1907-1912

ISSN: 0026-8976

Key Words: uranium tetrahalide; molecular structures; vibrational frequencies; BDE

Abstract: The molecular structures and vibrational frequencies of gaseous UX4 (X = F, Cl, Br and I) molecules have been investigated using generalized gradient approximation (GGA) functions (BP, BLYP, PBE and RPBE) with triplezeta polarized (TZP) basis set. Scalar relativistic effects are introduced via the zeroth-order regular approximation (ZORA) approach to the Dirac equation in the present study. Of the methods examined here the RPBE has the best performance in terms of the errors compared with experiment and reference for the vibrational frequencies. The bond dissociation energies (BDE) for U-X bonds in the UX4 were obtained using the RPBE method, and are in good agreement with experimental values. In addition, satisfactory calculated entropies of UX4 have also been obtained at temperatures ranging from 600 to 1200K in 50 steps using the same method.