title: Communication: Explicitly correlated four-component relativistic second-order Møller-Plesset perturbation theory.
abstract: We propose explicitly correlated Ansatz for four-component relativistic methods within the framework of the no-pair approximation. Kinetically balanced geminal basis is derived to satisfy the cusp conditions in the non-relativistic limit based on the Lévy-Leblend-like equation. Relativistic variants of strong-orthogonality projection operator (Ansätze 2α and 2β) suitable for practical calculations are introduced by exploiting the orthogonal complement of the large-component basis. A pilot implementation is performed for the second order Møller-Plesset perturbation theory.
authors.affiliation: Graduate School of System Informatics, Department of Computational Sciences, Kobe University, Nada-ku, Kobe 657-8501, Japan. tenno@cs.kobe-u.ac.jp
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Ten-no
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamaki