The change in the nature of bonding in the Li2 dimer under confinement

• Published in: International journal of quantum chemistry 2021-06, Vol.121 (12), p.n/a
• Main Authors: Robles‐Navarro, Andrés, Rodriguez‐Bautista, Mariano, Fuentealba, Patricio, Cárdenas, Carlos
• Format: Article
• Language: English
• Subjects: ab initio calculations; Atomic structure; Bonding strength; CASSCF; Chemistry; confined molecules; Confinement; Dimers; electron localization function; Electronic structure; Lithium; Molecular structure; Physical chemistry; Pressure effects; Quantum chemistry; Quantum physics
• ISSN: 0020-7608; 1097-461X
• DOI: 10.1002/qua.26644

Confinement and pressure have profound effects on the electronic structure of atoms and molecules. In this work, we study the effects of a harmonic confinement on the electronic structure of the lithium dimer. To do this, we use quantum chemistry methods that include much of the electronic correlation (Coupled Cluster and CASSCF). The confinement induces a change, with respect to the free molecule, in the electronic configuration of Li2. There is a critical confinement value for which the ground state stops being the singlet 1∑g+ and becomes the triplet 3∑g−. We also study changes in the bonding pattern. Li2 conserves the bonding pattern of the free molecule independently of the strength of confinement, as it is revealed by the electron localization function. The effects of confinement by a isotropic harmonic potential on the electronic structure of lithium dimer is examined with post‐Hartree‐Fock methods that include much of the electronic correlation (CCSD and CASSCF).