X2C-inspired approximation of the Dirac coupling operator in a multiwavelet basis

Abstract:We present a method to obtain the proven exact 2-component (X2C) method, normally applied to Gaussian-type fixed Hilbert bases, in an adaptative non-uniform grid basis of the Hilbert space, namely Multiwavelets. The X2C method manages to block-diagonalise the Dirac Hamiltonian restricted to the subspace of the basis, in an energy-independent manner. The method takes inspiration from the success of the atomic mean-field X2C method on the Gaussian bases to represent the coupling operator as a projector onto the small components of the eigenstates of the constituent atoms of the system.

Quantum Physics (quant-ph); Chemical Physics (physics.chem-ph)

arXiv:2610.07512 [quant-ph]

(or arXiv:2610.07512v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2610.07512 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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