EXCITED STATES OF CH$_5^+$ BY DIFFUSION MONTE CARLO

Abstract

Understanding the spectrum of CH$_5^+$ is a problem of long standing interest. Of particular interest is gaining a better understanding of the two high resolution spectra; one observed by White et. al {}}, and one that is partially assigned observed by the Nesbitt group. {}} Using excited state Diffusion Monte Carlo techniques in combination with symmetry adapted linear combinations of the internal coordinates of CH$_5^+$, obtained from group theoretical analysis of the G$_{240}$ CNPI group, we investigate the nature of the vibrationally, and rotationally excited states of CH$_5^+$. By probing CH$_5^+$ using these methods, we find that we are able to gain insights into the effects of the internal rotor motions of vibrationally excited states of CH$_5^+$.