A very high accuracy potential energy surface for H3
Abstract
An exact quantum Monte Carlo (EQMC) method was used to calculate the potential energy surface (PES) for the ground electronic state of H3 over a grid of about 76000 nuclear geometries. The absolute abinitio statistical or sampling error of the calculation was ±0.01 kcal mol^-1 for energies (V) smaller than 3 eV. This PES was fitted by a three-dimensional cubic spline method and the fitting accuracy was determined from a set of 3684 randomly selected nuclear geometries not used in the fitting. For the range V3 eV the rms fitting error was ±0.010 kcal mol^-1, and the absolute value of the corresponding maximum error was 0.018 kcal mol^-1. This fitted EQMC PES is an order of magnitude more accurate than the best PES previously obtained for this system. Detailed comparisons are made with previous PESs, for the more dynamically important nuclear configurations.
Additional Information
© Royal Society of Chemistry 1999 Received 10th November 1998, Accepted 22nd December 1998 Financial support from NSF Grants No. CHE 9632816 and CHE 9810050 is gratefully acknowledged. The calculations reported were performed on the 512 node Intel Paragon at Caltech's Center for Advanced Computing Research. We thank the sta�ff of the Center for their help. We also thank Dr. Drake L. Diedrich for calculating some points used for an independent verification of the statistical error in the present calculations.Files
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Additional details
- Eprint ID
- 4788
- Resolver ID
- CaltechAUTHORS:WUYpccp99
- Created
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2006-09-06Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field