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arXiv · 2308.03508

Tensorized orbitals for computational chemistry

Nicolas Jolly·Yuriel Núñez Fernández·Xavier Waintal
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Abstract

Choosing a basis set is the first step of a quantum chemistry calculation and it sets its maximum accuracy. This choice of orbitals is limited by strong technical constraints as one must be able to compute a large number of six dimensional Coulomb integrals from these orbitals. Here we use tensor network techniques to construct representations of orbitals that essentially lift these technical constraints. We show that a large class of orbitals can be put into ``tensorized'' form including the Gaussian orbitals, Slater orbitals, linear combination thereof as well as new orbitals beyond the above. Our method provides a path for building more accurate and more compact basis sets beyond what has been accessible with previous technology. As an illustration, we construct optimized tensorized orbitals and obtain a 85% reduction of the error on the energy of the $H_2$ molecules with respect to a reference double zeta calculation (cc-pvDz) of the same size.

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Nicolas Jolly, Yuriel Núñez Fernández, Xavier Waintal. 2023-08-07. Tensorized orbitals for computational chemistry. https://doi.org/10.1103/physrevb.111.245115

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