Direct computation of the quantum partition function by path-integral nested sampling

Bela Szekeres; Livia B. Partay; Edit Matyus

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arXiv · 1804.05987

Direct computation of the quantum partition function by path-integral nested sampling

Bela Szekeres·Livia B. Partay·Edit Matyus

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Abstract

In the present work we introduce a computational approach to the absolute rovibrational quantum partition function using the path-integral formalism of quantum mechanics in combination with the nested sampling technique. The numerical applicability of path-integral nested sampling is demonstrated for small molecules of spectroscopic interest. The computational cost of the method is determined by the evaluation time of a point on the potential-energy surface (PES). For efficient PES implementations, the path-integral nested-sampling method can be a viable alternative to the direct Boltzmann summation technique of variationally computed rovibrational energies, especially for medium-sized molecules and at elevated temperatures.

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Bela Szekeres, Livia B. Partay, Edit Matyus. 2018-04-17. Direct computation of the quantum partition function by path-integral nested sampling. https://arxiv.org/abs/1804.05987

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