Molecular clustering about a positive ion. Structures, energetics, and vibrational frequencies of the protonated hydrogen clusters H/sup +//sub 3/, H/sup +//sub 5/, H/sup +//sub 7/, and H/sup +//sub 9/

Journal Article · Tue Mar 15 00:00:00 EST 1983 · J. Chem. Phys.; (United States)

OSTI ID:5636930

Yamaguchi, Y; Gaw, J F; Schaefer, III, H F

The positive hydrogen clusters H/sup +/(H/sub 2/)/sub n/ for n = 1, 2, 3, 4 have been studied via nonempirical molecular electronic structure theory. Using double zeta (DZ) and double zeta plus polarization (DZ+P) basis sets, wave functions are reported at both the self-consistent field (SCF) and configuration interaction including all single and double excitations (CISD) levels of theory. In each case analytic gradient techniques have been used to locate stationary point geometries and to predict harmonic vibrational frequencies. The effects of electron correlation are shown to be greater for these loose molecular complexes than for ordinary molecules. Although H/sup +//sub 5/ in its lowest energy conformation is not qualitatively described as H/sup +//sub 3/xH/sub 2/, the larger molecular ions do fit the qualitative picture H/sup +//sub 3/(H/sub 2/)/sub n/, with H/sup +//sub 3/ as a nucleating center. Of special interest here are the ''new'' normal modes of these clusters, i.e., those modes having no counterpart in the isolated H/sup +//sub 3/ or H/sub 2/ species. There are 15 such vibrational degrees of freedom for H/sup +//sub 9/, and the resulting harmonic vibrational frequencies range from 775 cm/sup -1/ all the way down to 63 cm/sup -1/. Dissociation energies as a function of cluster size follow the pattern established experimentally by Hiraoka and Kebarle.

• Research Organization: Department of Chemistry and Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
• OSTI ID: 5636930
• Journal Information: J. Chem. Phys.; (United States), Vol. 78:6
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HYDROGEN
ELECTRONIC STRUCTURE
VIBRATIONAL STATES
CONFIGURATION INTERACTION
ION PAIRS
MOLECULAR STRUCTURE
SELF-CONSISTENT FIELD
ELEMENTS
ENERGY LEVELS
EXCITED STATES
NONMETALS
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory