CH[sub 5][sup +]: The never-ending story or the final word

Journal Article · Wed Sep 01 00:00:00 EDT 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.466147· OSTI ID:6275411

Schreiner, P R; Kim, S; Schaefer, III, H F; von Rague Schleyer, P ^[1]

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1. Contribution from the Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602 (United States) the Institut fuer Organische Chemie der Universitaet Erlangen-Nuernberg, Henkestrasse 42, D-8520 Erlangen (Germany)

The closely related [ital C][sub [ital s]](1), [ital C][sub [ital s]](2), and [ital C][sub 2[ital v]](3) structures of CH[sub 5][sup +] have been reinvestigated with high level [ital ab] [ital initio] theory through the coupled cluster with single and double substitutions (CCSD), and CCSD with perturbatively included connected triple excitations [CCSD(T)] levels, employing a triple-[zeta] plus double polarization functions basis set, with [ital f]-functions on carbon as well as [ital d]-functions on the hydrogens [TZ2P([ital f],[ital d])]. Vibrational frequencies have been computed up to TZ2P+[ital f] CCSD; the inclusion of [ital f]-functions on carbon is critical for the configuration interaction with single and double excitations (CISD) and coupled cluster methods using the triple-[zeta] basis sets. The changes in geometries between the CISD and CCSD levels are very small, e.g., the C--H bond lengths vary by at most 0.005 A. Thus, the optimizations are essentially converged within theoretical limits. The differences in energies of 1, 2, and 3 decrease and essentially vanish at the most sophisticated levels when the zero point vibrational energy corrections are applied. Hence, there is essentially [ital no] [ital barrier] to complete hydrogen scrambling.

• DOE Contract Number: FG09-87ER13811
• OSTI ID: 6275411
• Journal Information: Journal of Chemical Physics; (United States), Vol. 99:5; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HYDROCARBONS
GEOMETRY
VIBRATIONAL STATES
MOLECULAR IONS
CARBONIUM COMPOUNDS
CATIONS
CHEMICAL BONDS
CONFIGURATION INTERACTION
EXCITATION
MASS SPECTROSCOPY
OPTIMIZATION
CARBON COMPOUNDS
CHARGED PARTICLES
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
IONS
MATHEMATICS
ORGANIC COMPOUNDS
SPECTROSCOPY
664100* - Theory of Electronic Structure of Atoms & Molecules- (1992-)
664200 - Spectra of Atoms & Molecules & their Interactions with Photons- (1992-)