AB INITIO INVESTIGATIONS OF THE EXCITED ELECTRONIC STATES
AB INITIO INVESTIGATIONS OF THE EXCITED ELECTRONIC STATES OF Ca. OCa Wafaa M Fawzy Michael C Heaven
PREVIOUS STUDIES Ab initio studies on the ground and the first excited triplet state Level of theory: FV-CAS(10, 12)-MRCISD +Q Basis set: cc-pw. CVQZ-DK (Ca atoms) and cc-p. CVQZ (the O atom) Core-Valence Correlation Re = 1. 99521 Å (Te= 386. 1 cm-1); Re = 1. 99883 Å Ca+-O 2 --Ca+ Centro symmetric linear equilibrium structure Ostojic, Bunker, Schwerdtferger, Gertychm and Jensen, J. Mol. Str 1023 (2012) 101 -107
Is a multi-reference state Almost a single-reference state First excited singlet state? OR
CURRENT WORK Ab initio studies on the first excited singlet state Level of theory: SA-FV-CAS(10, 12)-MRCISD +Q Basis set: cc-pw. CVQZ-DK (for all atoms) All as implemented MOLPRO 2012 Core electrons of the Ca and O atoms were optimized but were not included in the correlation
INITIAL EXPLORATION OF ALL EXCITED STATES EXPLORATION OF THE EXCITED STATES Assumed linear geometry in all states Singlet states: two Ag, one B 1 u, two B 2 u, two B 3 u, two B 2 g, two B 3 g Triplet states: one B 1 u, two B 2 u, two B 3 u, two B 2 g, two B 3 g State average included eleven singlet and nine triplet states
Eleven Singlet and nine triplet states Symmetric stretch
The Region of the Symmetric stretch State
Calculation of the three-dimensional potential of ground state and the first excited singlet state State average included three singlet and one triplet states First, tests for the radial and the angular cuts through the PES
The one-d bend potentials of the states and R=1. 99897 Å R=2. 0337 Å
V(q)/ au Fit of the Bending Potential of the q/ radian State
V(q)/ au Fit of the Bending Potential of the A 1 B 2 State 3294 cm-1 q/ radian
The 1 -D Symmetric Stretch Potentials of the and A 1 B 2 states
Fit of the Symmetric Stretch Potential of the R 2 = 0. 99998 De = 66031 (177) cm-1 b = 1. 3808 (0. 007) Å-1 re = 2. 0337 (2. 3 x 10 -4) State
Fit of the Symmetric Stretch Potential of the A 1 B 2 State R 2 = 0. 99993 De = 70000 (177) cm-1 b = 1. 4075 (0. 007) Å-1 re = 1. 99897 (3. 73 x 10 -4)
Spectroscopic Parameters of the and A 1 B 2 States All Parameters are in Units of cm-1 a. Ostojic, b. Laser Bunker, Schwerdtferger, Gertychm and Jensen, J. Mol. Str 1023 (2012) 101 -107 Induced Fluorescence Spectroscopy of Jet-Cooled Ca. OCa, M. Sullivan, D. Frohman, M. Heaven, W. Fawzy, Paper RI 10
ACCURATE VIBRATIONAL CALCULATIONS 1) Fit the full ab initio surface to a potential function 2) Use an appropriate quantum mechanical model for the vibrational calculations Comparison between the rigid-bender model and the DVR method We calculated the ground state vibrational energy levels using the computer code of Ref. 3 and the coefficients of Ref. 4. We used the potential energy function as Results of the DVR model are in excellent agreement with those of Ref 4. 1 H. Y. 2 J. 3 J. 4 Mussa, J. Tennyson, Comput. Phys. Commun. 128 (2000) 434. Tennyson, B. T. Sutcliffe, Internat. J. Quantum Chem. 42 (1992) 941 Tennyson, Maxim A. Kostin, P. Barletta, G. J. Harris, O. L. Polyansky, J. Ramanlal, N. F. Zobov, CPC 163 (2004) 85 -116 Bunker, Schwerdtferger, Gertychm and Jensen, J. Mol. Str 1023 (2012) 101 -107
NEAR FUTURE PLANS Full vibrational calculations using the DVR method as it was implemented in the computer code of Tennyson and coworkers End
- Slides: 17