Transcorrelated Methods Applied to Second Row Elements

TL;DR

This paper demonstrates that transcorrelated methods significantly improve the convergence of total energies and ionisation potentials for second row elements, achieving chemically accurate results with smaller basis sets.

Contribution

It applies transcorrelated Hamiltonians with quantum Monte Carlo and coupled cluster methods to second row elements, showing enhanced convergence and accuracy.

Findings

Transcorrelation accelerates basis set convergence.

Chemically accurate results with cc-pVTZ basis.

Effective with frozen core in post-Hartree--Fock calculations.

Abstract

We explore the applicability of the transcorrelated method to the elements in the second row of the periodic table. We use transcorrelated Hamiltonians in conjunction with full configuration interaction quantum Monte Carlo and coupled cluster techniques to obtain total energies and ionisation potentials, investigating their dependence on the nature and size of the basis sets used. Transcorrelation accelerates convergence to the complete basis set limit relative to conventional approaches, and chemically accurate results can generally be obtained with the cc-pVTZ basis, even with a frozen Ne core in the post-Hartree--Fock treatment.