### Abstract

A modified version of the Shepard interpolation scheme proposed recently by Collins et al. is used to determine a potential energy surface for the H_{2}-H reaction. Our modifications are based on preliminary calculations in which the Liu-Siegbahn-Truhlar-Horowitz surface for H_{3} is used to study convergence of the Shepard procedure. Included in the modifications are changes to the form of the weight functions, the coordinate sets used in the zeroth-order surface, and the transformation of the Cartesian first and second derivatives to internal coordinates. The new ab initio potential energy surface is based on calculations using the basis set of Siegbahn and Liu and second order Møller-Plesset (MP2) perturbation calculations. We have not experienced convergence problems with the self-consistent-field iteration while "growing" the surface. Furthermore, a converged fit can be obtained using only 85 ab initio calculations. This demonstrates that the Shepard interpolation scheme is a powerful candidate for automatic determination of medium quality potential surfaces for dynamical calculations.

Original language | English |
---|---|

Pages (from-to) | 3558-3568 |

Number of pages | 11 |

Journal | Journal of Chemical Physics |

Volume | 107 |

Issue number | 9 |

Publication status | Published - Sep 1 1997 |

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### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics

### Cite this

**Automatic potential energy surface generation directly from ab initio calculations using Shepard interpolation : A test calculation for the H _{2}+H system.** / Ishida, Toshimasa; Schatz, George C.

Research output: Contribution to journal › Article

_{2}+H system',

*Journal of Chemical Physics*, vol. 107, no. 9, pp. 3558-3568.

}

TY - JOUR

T1 - Automatic potential energy surface generation directly from ab initio calculations using Shepard interpolation

T2 - A test calculation for the H2+H system

AU - Ishida, Toshimasa

AU - Schatz, George C

PY - 1997/9/1

Y1 - 1997/9/1

N2 - A modified version of the Shepard interpolation scheme proposed recently by Collins et al. is used to determine a potential energy surface for the H2-H reaction. Our modifications are based on preliminary calculations in which the Liu-Siegbahn-Truhlar-Horowitz surface for H3 is used to study convergence of the Shepard procedure. Included in the modifications are changes to the form of the weight functions, the coordinate sets used in the zeroth-order surface, and the transformation of the Cartesian first and second derivatives to internal coordinates. The new ab initio potential energy surface is based on calculations using the basis set of Siegbahn and Liu and second order Møller-Plesset (MP2) perturbation calculations. We have not experienced convergence problems with the self-consistent-field iteration while "growing" the surface. Furthermore, a converged fit can be obtained using only 85 ab initio calculations. This demonstrates that the Shepard interpolation scheme is a powerful candidate for automatic determination of medium quality potential surfaces for dynamical calculations.

AB - A modified version of the Shepard interpolation scheme proposed recently by Collins et al. is used to determine a potential energy surface for the H2-H reaction. Our modifications are based on preliminary calculations in which the Liu-Siegbahn-Truhlar-Horowitz surface for H3 is used to study convergence of the Shepard procedure. Included in the modifications are changes to the form of the weight functions, the coordinate sets used in the zeroth-order surface, and the transformation of the Cartesian first and second derivatives to internal coordinates. The new ab initio potential energy surface is based on calculations using the basis set of Siegbahn and Liu and second order Møller-Plesset (MP2) perturbation calculations. We have not experienced convergence problems with the self-consistent-field iteration while "growing" the surface. Furthermore, a converged fit can be obtained using only 85 ab initio calculations. This demonstrates that the Shepard interpolation scheme is a powerful candidate for automatic determination of medium quality potential surfaces for dynamical calculations.

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UR - http://www.scopus.com/inward/citedby.url?scp=0001201569&partnerID=8YFLogxK

M3 - Article

VL - 107

SP - 3558

EP - 3568

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 9

ER -