TY - JOUR
T1 - Ab initio calculations on the X̃1A′ and Ã1A″1 states of HPO and Franck-Condon simulation of the single vibronic level emission spectra of HPO and DPO
AU - Lee, Edmond P F
AU - Mok, Kam Wah
AU - Chau, Foo Tim
AU - Dyke, John M.
PY - 2007/12/14
Y1 - 2007/12/14
N2 - Minimum-energy geometries and relative electronic energies of the X̃ A′1 and à A″1 states of HPO have been computed employing the coupled-cluster single-double plus perturbative triple excitations {RCCSD(T)} and/or complete-active-space self-consistent-field (CASSCF) multireference internally contracted configuration interaction (MRCI) methods with basis sets of up to the augmented correlation-consistent polarized-valence quintuple-zeta (aug-cc-pV5Z) quality. In addition, RCCSD(T)/aug-cc-pVQZ and CASSCF/MRCI/aug-cc-pVQZ potential energy functions, anharmonic vibrational wave functions, and energies involving all three vibrational modes for both electronic states of HPO and DPO, and Franck-Condon factors between the two electronic states, which allow for Duschinsky rotation and anharmonicity, were computed. Computed Franck-Condon factors were then used to simulate single vibronic level (SVL) emission spectra recently reported by Tackett and Clouthier [J. Chem. Phys. 117, 10604 (2002)]. Excellent agreement between the simulated and observed spectra was obtained for the à A″1 (1,0,0) → X̃ A′1 SVL emission of HPO and DPO, when the best estimated ab initio geometries of the two states, which include contributions from core correlation and extrapolation to the complete basis set limit, were used in the simulation, suggesting that the best estimated ab initio geometry of the à A″1 state of HPO, particularly the bond angle of 94.5°, is more reliable than the available experimentally derived geometry. A discussion on the geometrical parameters derived from rotational constants obtained from the rotational analysis of a high-resolution spectrum and from Franck-Condon simulation of the vibrational structure of an electronic spectrum is given.
AB - Minimum-energy geometries and relative electronic energies of the X̃ A′1 and à A″1 states of HPO have been computed employing the coupled-cluster single-double plus perturbative triple excitations {RCCSD(T)} and/or complete-active-space self-consistent-field (CASSCF) multireference internally contracted configuration interaction (MRCI) methods with basis sets of up to the augmented correlation-consistent polarized-valence quintuple-zeta (aug-cc-pV5Z) quality. In addition, RCCSD(T)/aug-cc-pVQZ and CASSCF/MRCI/aug-cc-pVQZ potential energy functions, anharmonic vibrational wave functions, and energies involving all three vibrational modes for both electronic states of HPO and DPO, and Franck-Condon factors between the two electronic states, which allow for Duschinsky rotation and anharmonicity, were computed. Computed Franck-Condon factors were then used to simulate single vibronic level (SVL) emission spectra recently reported by Tackett and Clouthier [J. Chem. Phys. 117, 10604 (2002)]. Excellent agreement between the simulated and observed spectra was obtained for the à A″1 (1,0,0) → X̃ A′1 SVL emission of HPO and DPO, when the best estimated ab initio geometries of the two states, which include contributions from core correlation and extrapolation to the complete basis set limit, were used in the simulation, suggesting that the best estimated ab initio geometry of the à A″1 state of HPO, particularly the bond angle of 94.5°, is more reliable than the available experimentally derived geometry. A discussion on the geometrical parameters derived from rotational constants obtained from the rotational analysis of a high-resolution spectrum and from Franck-Condon simulation of the vibrational structure of an electronic spectrum is given.
UR - http://www.scopus.com/inward/record.url?scp=36849040955&partnerID=8YFLogxK
U2 - 10.1063/1.2790892
DO - 10.1063/1.2790892
M3 - Journal article
C2 - 18067355
SN - 0021-9606
VL - 127
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 21
M1 - 214305
ER -