Calculating Anharmonic Vibrational States Without a Pre-Existing Potential Energy Surface

Details Calculating Anharmonic Vibrational States Without a Pre-Existing Potential Energy Surface Calculating Anharmonic Vibrational States Without a Pre-Existing Potential Energy Surface

Jun 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010mss..conferj06p&link_type=abstract

"International Symposium On Molecular Spectroscopy, 65th Meeting, Held 21-25 June, 2010 at Ohio State University. http://molspec

Statistics

Computation

Theory

Scientific paper

The calculation of anharmonic vibrational states, especially of highly fluxional systems, is complicated by the need to first obtain the full-dimensional potential energy surface (PES). Reduced dimensional approaches, where appropriate, can greatly help to ease the computational cost of these calculations but their application is highly system dependent, preventing the development of a general methodology. We report here our recent efforts to develop an algorithm capable of accurately calculating anharmonic vibrational energies, even for very floppy systems, without first obtaining a PES. More specifically, the potential energy and G-matrix elements are calculated on a grid of points obtained from a Monte Carlo sampling of the most important regions of configuration space. The Hamiltonian matrix is then constructed using an evolving basis which, with each iteration, captures the effect of building H from an ever-increasing harmonic oscillator basis despite the fact that the actual dimensionality of H is fixed throughout the calculation. This latter property of the algorithm also greatly reduces the size of basis needed for the calculation relative to more traditional variational approaches. The results obtained from the application of our method to several test systems will also be reported along with its observed convergence properties.

Affiliated with

Also associated with

No associations

Rating

Calculating Anharmonic Vibrational States Without a Pre-Existing Potential Energy Surface does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Calculating Anharmonic Vibrational States Without a Pre-Existing Potential Energy Surface, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Calculating Anharmonic Vibrational States Without a Pre-Existing Potential Energy Surface will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1592889