Bulletin of the American Physical Society
APS March Meeting 2018
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session Y02: Structure and Spectroscopy
11:15 AM–2:03 PM,
Friday, March 9, 2018
LACC Room: 150B
Sponsoring Unit: DCP
Chair: Stephen Bradforth, Univ of Southern California
Abstract: Y02.00009 : Calculations of vibrational spectra with rectangular collocation: suitability for catalytic systems, tests of PES representations and selection of important regions of space*
12:51 PM–1:03 PM
(Chemistry, Queen's University)
We present the latest developments in the rectangular collocation method to compute vibrational spectra. Rectangular collocation allows using a small number of fixed-shape or tuned basis functions of various forms to compute anharmonic spectra from a relatively small number of potential energy surface (PES) samples. It is well suited for calculations of anharmonic spectra when an analytic PES is unavailable and when underlying ab initio calculations are costly, such as molecules on surfaces. We show that collocation points can be placed in important regions of space further reducing computational cost. Accurate anharmonic spectra for a four-atomic molecules are computable on a desktop. We compare spectra on PESs fitted with neural networks and Gaussian process regression and show that the method also permits to get a clearer understanding of how errors due to PES representation translate into errors in the spectrum.
*This was was supported by the Ministry of Education of Singapore and Singapore (SM) and the Natural Sciences and Engineering Research Council of Canada (SM). The authors thank Xiaogang Wang, Roman Krems, Aditya Kamath, and Rodrigo A. Vargas-Hernández for contributing to some of the research.
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