Theoretical investigation of atmospheric sulfur chemistry. 1. The HSO/HOS energy separation and the heat formation of HSO, HOS, and HS/sub 2/
The energy separation between the ground-state structure of HSO and HOS has been determined by using two independent ab initio methods. In the first method, the optimized geometry of all species was obtained at the HF/6-31G(d) level, as were harmonic vibrational frequencies for zero-point energy corrections. The energies were calculated by using fourth-order Moeller-Plesset perturbation theory and a 6-31G(d,p) basis set. After corrections for extrapolation of the Moeller-Plesset series to infinite order and extension of the basis set to include diffuse sp-, extra d-, and f-type Gaussian functions, the predicted energy separation, including zero-point vibrational effects, is 2.5 kcal/mol. HOS is the more stable isomer. The second method uses a double-zeta basis augmented with an extra set of p functions and two sets of d functions on the sulfur and oxygen atoms and a double-zeta + p basis on hydrogen. With this basis, equilibrium structures of HSO and HOS were obtained from MCSCF calculations; the energy separation between these structures was corrected by using large scale configuration interaction. 49 references, 8 tables.
- Research Organization:
- Molecular Research Institute, Palo Alto, CA
- OSTI ID:
- 6444799
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 89:21
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
OXYGEN COMPOUNDS
STRUCTURAL CHEMICAL ANALYSIS
SULFUR COMPOUNDS
CONFIGURATION INTERACTION
CONFORMATIONAL CHANGES
FORMATION HEAT
ISOMERS
MOLECULAR STRUCTURE
PERTURBATION THEORY
SELF-CONSISTENT FIELD
THEORETICAL DATA
VIBRATIONAL STATES
DATA
ENERGY LEVELS
ENTHALPY
EXCITED STATES
INFORMATION
NUMERICAL DATA
PHYSICAL PROPERTIES
REACTION HEAT
THERMODYNAMIC PROPERTIES
400201* - Chemical & Physicochemical Properties
510200 - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)