Approaching the basis-set limit of the dRPA correlation energy with explicitly correlated and Projector Augmented-wave methods

• Published in: arXiv.org
• Main Authors: Humer, Moritz, Harding, Michael E, Schlipf, Martin, Taheridehkordi, Amir, Sukurma, Zoran, Klopper, Wim, Kresse, Georg
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 31.08.2022
• Subjects: Approximation; Atomizing; Correlation; Density functional theory; Exchanging; Mathematical analysis; Orbitals; Physics - Chemical Physics; Physics - Computational Physics; Plane waves
• DOI: 10.48550/arxiv.2208.14726

The direct random-phase approximation (dRPA) is used to calculate and compare atomization energies for the HEAT set and 10 selected molecules of the G2-1 set using both plane waves and Gaussian-type orbitals. We describe detailed procedures to obtain highly accurate and well converged results for the projector augmented-wave (PAW) method as implemented in the Vienna Ab-initio Simulation Package (VASP) as well as the explicitly correlated dRPA-F12 method as implemented in the TURBOMOLE package. The two approaches agree within chemical accuracy (1 kcal/mol) for the atomization energies of all considered molecules, both for the exact exchange as well as for the dRPA. The root mean-square deviation is 0.41 kcal/mol for the exact exchange (evaluated using density functional theory orbitals) and 0.33 kcal/mol for exact exchange plus the random-phase approximation.