An ab initio study of the structures and heats of formation of SiH sub m F sub n sup + (m + n = 1-4)

Journal Article · Thu Sep 20 04:00:00 EDT 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100382a024· OSTI ID:6444315

Ignacio, E W; Schlegel, H B ^[1]

---

1. Wayne State Univ., Detroit, MI (USA)

The equilibrium geometries of SiH{sub m}F{sub n}{sup +} (m + n = 1-4) were determined at the Hartree-Fock level by using the 3-21G and 6-31G* basis sets. The structures of SiH, SiF, and SiH{sub 2{minus}n}F{sub n}{sup +} resemble the neutral molecules; the tricoordinate cations are planar, whereas the neutral radicals are pyramidal. The SiH{sub 4{minus}n}F{sub n}{sup +} distort to form a complex between a silicon-containing cation and a neutral atom or diatom: SiH{sub 2}{sup +}-H{sub 2}, SiHF{sup +}-HF, SiHF{sup +}-HF, SiF{sub 2}{sup +}-HF, and SiF{sub 3}{sup +}-F are the lowest energy structures. Adiabatic ionization potentials and proton affinities were calculated at the MP4SDTQ/6-31G** level. Heats of formation were computed by the bond additivity correction method and from the ionization potentials and proton affinities.

• OSTI ID: 6444315
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:19; ISSN JPCHA; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
CALCULATION METHODS
ENERGY LEVELS
ENTHALPY
FORMATION HEAT
HARTREE-FOCK METHOD
IONIZATION POTENTIAL
MOLECULAR STRUCTURE
PHYSICAL PROPERTIES
REACTION HEAT
SILICON COMPOUNDS
THERMODYNAMIC PROPERTIES