Full Breit Hamiltonian in the Multiwavelets Framework

• DOI: 10.1021/acs.jctc.3c01056
• Publication Date: 2024-01-01T15:53:10Z
• Authors: Christian Tantardini; Roberto Di Remigi...; Magnar Bjørgve; Stig Rune Jensen; Luca Frediani
• Keywords: Hamiltonian (control theory); Basis (linear algebra)

New techniques in core–electron spectroscopy are necessary to resolve the structures of oxides f-elements and other strongly correlated materials that present only as powders not single crystals. Thus, accurate quantum chemical methods must be developed calculate core spectroscopic properties such materials. In this contribution, we an important development direction, extending our fully adaptive real-space multiwavelet basis framework tackle four-component Dirac-Coulomb-Breit Hamiltonian. We show multiwavelets can reproduce one-dimensional grid-based approaches. They however a three-dimensional approach which later extended molecules Our implementation attained precise results irrespective chosen nuclear model, provided error threshold is tight enough polynomial sufficiently large. Furthermore, confirmed two-electron species, magnetic Gauge contributions from s-orbitals identical magnitude account for experimental evidence K L edges.