Vibronic coupling in the first four electronic states of CH₂F⁺₂

† Dedicated to Professor Sourav Pal on the occassion of his 60th birthday.

Abstract

Vibronic coupling in the energetically lowest first four electronic states of CH₂F⁺₂ is studied in this paper. A model 4×4 Hamiltonian is constructed in a diabatic electronic representation employing normal coordinates of vibrational modes and standard vibronic coupling theory. Extensive ab initio quantum chemistry calculations are carried out to determine the parameters of the Hamiltonian and energetic ordering of the electronic states. The topographical features of the latter are examined at length and several conical intersections are established. Nuclear dynamics calculations on coupled electronic states are carried out from first principles by propagating wave packet. Theoretically calculated broad band vibronic structure of the four states are found to be in good accord with the experimental results.

Keywords:

• vibronic coupling
• diabatic Hamiltonian
• conical intersection

Acknowledgements

This study was supported in part through a research grant (Grant no. SB/S1/PC-052/2013) from the DST, New Delhi. Rudraditya Sarkar acknowledges the UGC, New Delhi for a Doctoral Fellowship. Computational facility provided by the CMSD, University of Hyderabad is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

† Dedicated to Professor Sourav Pal on the occassion of his 60th birthday.

Additional information

Funding

This study was supported in part through a research grant [grant number SB/S1/PC-052/2013] from the DST, New Delhi