### Abstract

We define and discuss the properties of manifolds of polynomials J_{n}(t, x) and R_{n}(t, x), called Rys polynomials, which are orthonormal with respect to the weighting factor exp(-xt^{2}) on a finite interval of t. Numerical quadrature based on Rys polynomials provides an alternative approach to the computation of integrals commonly encountered in molecular quantum mechanics. This gives rise to a curve fitting problem for the roots and quadrature weights as a function of the x parameter. We have used Chebyshev approximation for small x and an asymptotic expansion for large x. A modified Christoffel-Darboux equation applicable to Rys polynomials is derived and used to obtain alternative formulas for Rys quadrature weight factors.

Original language | English |
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Pages (from-to) | 144-165 |

Number of pages | 22 |

Journal | Journal of Computational Physics |

Volume | 21 |

Issue number | 2 |

DOIs | |

Publication status | Published - 1976 |

### ASJC Scopus subject areas

- Computer Science Applications
- Physics and Astronomy(all)

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## Cite this

*Journal of Computational Physics*,

*21*(2), 144-165. https://doi.org/10.1016/0021-9991(76)90008-5