title: First principles potential for the acetylene dimer and refinement by fitting to experiments.
abstract: We report the definition and refinement of a new first principles potential for the acetylene dimer. The ab initio calculations were performed with the DFT-SAPT combination of symmetry-adapted intermolecular perturbation method and density functional theory, and fitted to a model site-site functional form. Comparison of the calculated microwave spectrum with experimental data revealed that the barriers to isomerization were too low. This potential was refined by fitting the model parameters in order to reproduce the observed transitions, an excellent agreement within ~1 MHz being achieved.
authors.affiliation: Institut Charles Gerhardt (CTMM)-UMR 5253, CC 1501, Université Montpellier II-CNRS, 34095 Montpellier Cedex 05, France. claude.leforestier@univ-montp2.fr
authors.forename: Claude
authors.initials: C
authors.lastname: Leforestier
authors.forename: Adem
authors.initials: A
authors.lastname: Tekin
authors.forename: Georg
authors.initials: G
authors.lastname: Jansen
authors.forename: Michel
authors.initials: M
authors.lastname: Herman