title: Orbital Entanglement in Bond-Formation Processes.
abstract: The accurate calculation of the (differential) correlation energy is central to the quantum chemical description of bond-formation and bond-dissociation processes. In order to estimate the quality of single- and multireference approaches for this purpose, various diagnostic tools have been developed. In this work, we elaborate on our previous observation [J. Phys. Chem. Lett.2012, 3, 3129] that one- and two-orbital-based entanglement measures provide quantitative means for the assessment and classification of electron correlation effects among molecular orbitals. The dissociation behavior of some prototypical diatomic molecules features all types of correlation effects relevant for chemical bonding. We demonstrate that our entanglement analysis is convenient to dissect these electron correlation effects and to provide a conceptual understanding of bond-forming and bond-breaking processes from the point of view of quantum information theory.
authors.affiliation: ETH Zürich , Laboratory of Physical Chemistry, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland.
authors.forename: Katharina
authors.initials: K
authors.lastname: Boguslawski
authors.affiliation: ETH Zürich , Laboratory of Physical Chemistry, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Tecmer
authors.affiliation: Strongly Correlated Systems ″Lendület″ Research Group, Wigner Research Center for Physics , H-1525 Budapest, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Barcza
authors.affiliation: Strongly Correlated Systems ″Lendület″ Research Group, Wigner Research Center for Physics , H-1525 Budapest, Hungary.
authors.forename: Örs
authors.initials: Ö
authors.lastname: Legeza
authors.affiliation: ETH Zürich , Laboratory of Physical Chemistry, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Reiher