Computation of the short range repulsion energy from correlated monomer wavefunctions in van der Waals dimers containing He, Ne, and N2

• Published in: Molecular physics Vol. 66; no. 5; pp. 929 - 953
• Main Authors: Rijks, W., Gerritsen, M., Wormer, P.E.S.
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis Group 10.04.1989; Taylor & Francis
• Subjects: Atomic and molecular collision processes and interactions; Atomic and molecular physics; Exact sciences and technology; Interatomic and intermolecular potentials and forces, potential energy surfaces for collisions; Physics; Helium Atoms; Diatomic molecule; Two atom system; Nitrogen Molecules; Exchange interaction; Theoretical study; Van der Waals interaction; Configuration interaction; Neon Atoms; SD CI method; Inorganic compound; Two molecule system
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268978900100641

The first order Coulomb plus exchange energy between two closed shell monomers is computed in a non-orthogonal natural orbital formalism. SD-CI monomer wavefunctions were used in order to account for the intramolecular correlation effect. Approximations to the SD-CI wavefunctions and some restraints to the dimer orbital basis are investigated for He 2 . These result in a method which is applicable to larger dimers. This method is applied to dimers consisting of He, Ne, and N 2 . It is shown that it is possible to obtain reliable potential energy surfaces from this short range contribution, combined with damped dispersion energy terms.