Molecular Eigensolution Symmetry Analysis and Fine Structure

International Journal of Molecular Sciences

William G. Harter¹ 

[1]Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA

关键词: symmetry;    molecular dynamics;    tunneling;    level clusters;   

DOI  :  10.3390/ijms14010714

来源: mdpi

【 摘 要 】

Spectra of high-symmetry molecules contain fine and superfine level cluster structure related to J-tunneling between hills and valleys on rovibronic energy surfaces (RES). Such graphic visualizations help disentangle multi-level dynamics, selection rules, and state mixing effects including widespread violation of nuclear spin symmetry species. A review of RES analysis compares it to that of potential energy surfaces (PES) used in Born–Oppenheimer approximations. Both take advantage of adiabatic coupling in order to visualize Hamiltonian eigensolutions. RES of symmetric and D₂ asymmetric top rank-2-tensor Hamiltonians are compared with O_h spherical top rank-4-tensor fine-structure clusters of 6-fold and 8-fold tunneling multiplets. Then extreme 12-fold and 24-fold multiplets are analyzed by RES plots of higher rank tensor Hamiltonians. Such extreme clustering is rare in fundamental bands but prevalent in hot bands, and analysis of its superfine structure requires more efficient labeling and a more powerful group theory. This is introduced using elementary examples involving two groups of order-6 (C₆ and D₃~C_3v), then applied to families of O_h clusters in SF₆ spectra and to extreme clusters.

【 授权许可】

CC BY   
© 2013 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.