Electronic states and potential energy surfaces of SeH/sub 2/ and SeH/sub 2//sup +/
Complete active space MCSCF (CASSCF) followed by second-order configuration interaction (SOCI) calculations are carried out on seven electronic states of SeH/sub 2/ and the lowest state of the SeH/sub 2//sup +/ ion. The potential energy surfaces of three electronic states (/sup 1/A/sub 1/, /sup 3/B/sub 1/, /sup 1/B/sub 1/) of SeH/sub 2/ are obtained by using the CASSCF method. The CASSCF/SOCI calculations yield a /sup 1/A/sub 1/ ground state with a Se-H bond length of 1.461 /angstrom/ and a H-Se-H bond angle of 91.5/degrees/. The SOCI bond energy D/sub 0/(HSe-H) is calculated to be 3.45 eV in excellent agreement with a recent experimental value of 3.42 eV reported by Gibson et al. The SOCI atomization energy of the SeH/sub 2/ molecule is calculated to be 6.67 eV or 154 kcal/mol. The enthalpy of formation ..delta..H/sub f/ of the SeH/sub 2/ molecule is deduced to be -51 kcal/mol. The effect of extension of basis sets on the vertical separations of the seven states of SeH/sub 2/ molecule is deduced to be -51 kcal/mol. The effect of extension of basis sets on the vertical separations of the seven states of SeH/sub 2/ considered here is studied by employing a large (5s5p8d/5s5p5d) basis set. The bending potential energy surfaces of SeH/sub 2/ reveal that the Se(/sup 1/D) atom inserts into H/sub 2/ spontaneously to form the bent SeH/sub 2/(/sup 1/A/sub 1/) molecule while the Se(/sup 3/P) atom has to surmount a large barrier to the insertion into H/sub 2/. The dipole moment of SeH/sub 2/ calculated by using the SOCI method employing an extended (4s4p4d) basis set is 0.712 D with the polarity Se/sup -/H/sup +/. The effect of f functions on the properties of the ground state of SeH/sub 2/ is also studied.
- Research Organization:
- Arizona State Univ., Tempe (USA)
- OSTI ID:
- 6260069
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 92:16
- Country of Publication:
- United States
- Language:
- English
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PHYSICAL AND ANALYTICAL CHEMISTRY
SELENIUM HYDRIDES
ELECTRONIC STRUCTURE
BOND ANGLE
BOND LENGTHS
CATIONS
CONFIGURATION INTERACTION
FORMATION FREE ENTHALPY
POTENTIAL ENERGY
SELF-CONSISTENT FIELD
THEORETICAL DATA
VIBRATIONAL STATES
CHARGED PARTICLES
DATA
DIMENSIONS
ENERGY
ENERGY LEVELS
EXCITED STATES
FREE ENTHALPY
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
IONS
LENGTH
NUMERICAL DATA
PHYSICAL PROPERTIES
SELENIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
400201* - Chemical & Physicochemical Properties