Relativistic Complete Active Space Self-consistent-Field Method with a Hierarchy of Exact Two-Component Hamiltonians

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Wang, Xubo, Wang, Sen, Wu, Yixuan, Cheng, Lan
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866911473999020032
author Wang, Xubo
Wang, Sen
Wu, Yixuan
Cheng, Lan
author_facet Wang, Xubo
Wang, Sen
Wu, Yixuan
Cheng, Lan
contents The development of a novel exact two-component (X2C) scheme with the inclusion of the picture-change correction for the fluctuation potential, the X2Ccorr scheme, is reported, hereby establishing a hierarchy of X2C schemes with systematic improvement for the treatments of relativistic two-electron contributions. Using benchmark X2C complete active space self-consistent-field (CASSCF) calculations for zero-field splittings in chalcogen diatomics, the contributions of two-electron spin-orbit coupling, electron spin-spin coupling, and quantum electrodynamics are carefully analyzed. The capability of the new Cholesky decomposition-based implementation for relativistic two-component CASSCF method using super-configuration-interaction algorithms is further demonstrated with calculations for the low-lying electronic states of neodymium aqua-ions with up to the second coordination shells.
format Preprint
id arxiv_https___arxiv_org_abs_2602_24236
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Relativistic Complete Active Space Self-consistent-Field Method with a Hierarchy of Exact Two-Component Hamiltonians
Wang, Xubo
Wang, Sen
Wu, Yixuan
Cheng, Lan
Chemical Physics
The development of a novel exact two-component (X2C) scheme with the inclusion of the picture-change correction for the fluctuation potential, the X2Ccorr scheme, is reported, hereby establishing a hierarchy of X2C schemes with systematic improvement for the treatments of relativistic two-electron contributions. Using benchmark X2C complete active space self-consistent-field (CASSCF) calculations for zero-field splittings in chalcogen diatomics, the contributions of two-electron spin-orbit coupling, electron spin-spin coupling, and quantum electrodynamics are carefully analyzed. The capability of the new Cholesky decomposition-based implementation for relativistic two-component CASSCF method using super-configuration-interaction algorithms is further demonstrated with calculations for the low-lying electronic states of neodymium aqua-ions with up to the second coordination shells.
title Relativistic Complete Active Space Self-consistent-Field Method with a Hierarchy of Exact Two-Component Hamiltonians
topic Chemical Physics
url https://arxiv.org/abs/2602.24236