title: Hybrid and Constrained Resolution-of-Identity Techniques for Coulomb Integrals.
abstract: The introduction of auxiliary bases to approximate molecular orbital products has paved the way to significant savings in the evaluation of four-center two-electron Coulomb integrals. We present a generalized dual space strategy that sheds a new light on variants over the standard density and Coulomb-fitting schemes, including the possibility of introducing minimization constraints. We improve in particular the charge- or multipole-preserving strategies introduced respectively by Baerends and Van Alsenoy that we compare to a simple scheme where the Coulomb metric is used for lowest angular momentum auxiliary orbitals only. We explore the merits of these approaches on the basis of extensive Hartree-Fock and MP2 calculations over a standard set of medium size molecules.
authors.affiliation: INAC, SP2M/L_Sim, CEA/UJF Cedex 09, Université Grenoble Alpes , 38054 Grenoble, France.
authors.forename: Ivan
authors.identifier: http://orcid.org/0000-0003-4713-1174
authors.initials: I
authors.lastname: Duchemin
authors.affiliation: Université Grenoble Alpes , CNRS, Inst NEEL, F-38042 Grenoble, France.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Université Grenoble Alpes , CNRS, Inst NEEL, F-38042 Grenoble, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Blase