USING DIFFUSION MONTE CARLO TO PROBE ROTATIONAL EXCITED STATES
Loading...
Date
2009
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Since its inception in 1975 by Anderson,}, {\underline{63}}, 1499 (1975).} Diffusion Monte Carlo (DMC) has been successfully applied to a wide range of electronic and vibrational problems. In the latter case, it has been shown to be a powerful method for studying highly fluxional systems exhibiting large amplitude vibrational motions. We report here our recent work developing a new DMC algorithm capable of treating rotational excited states. We first develop the appropriate coordinates, nodal structures, and re-crossing corrections for this problem. Then, using H$_3$O$^+$ and D$_3$O$^+$ as model systems,}, {\underline{118}}, 5431 (2003).} we show that our method can successfully describe a range of rotational states from $\mid\!\!0,0,0\rangle$ to $\frac{1}{\sqrt{2}} \, (\mid\!\!10,10,0 \rangle + \!\!\mid \!\! 10,-10,0 \rangle)$. In particular, we examine the combined effects of rotational and zero-point vibrational motion on the geometric structure of the molecules. Finally, we find the $\mid \!\! 10,0,0 \rangle$ state to be somewhat problematic but show that the problem is straightforward to identify and has a well-defined solution.
Description
J. B. Anderson, {\it{J. Chem. Phys.X. Huang, S. Carter, and J. Bowman, {\it{J. Chem. Phys.
Author Institution: Department of Chemistry, The Ohio State University, Columbus, OH 43210
Author Institution: Department of Chemistry, The Ohio State University, Columbus, OH 43210