title: Electronic structures and geometries of the XF3 (X = Cl, Br, I, At) fluorides.
abstract: The potential energy surfaces of the group 17 XF3 (X = Cl, Br, I, At) fluorides have been investigated for the first time with multiconfigurational wave function theory approaches. In agreement with experiment, bent T-shaped C(2v) structures are computed for ClF3, BrF3, and IF3, while we predict that an average D(3h) structure would be experimentally observed for AtF3. Electron correlation and scalar relativistic effects strongly reduce the energy difference between the D(3h) geometry and the C(2v) one, along the XF3 series, and in the X = At case, spin-orbit coupling also slightly reduces this energy difference. AtF3 is a borderline system where the D(3h) structure becomes a minimum, i.e., the pseudo-Jahn-Teller effect is inhibited since electron correlation and scalar-relativistic effects create small energy barriers leading to the global C(2v) minima, although both types of effects interfere.
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 Rue A. Kastler, BP 20722, 44307 Nantes Cedex 3, France.
authors.forename: Dumitru-Claudiu
authors.initials: DC
authors.lastname: Sergentu
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, Case Courier 137, 4 Place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Amaouch
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, Case Courier 137, 4 Place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Pilmé
authors.affiliation: CEISAM, UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Galland
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 Rue A. Kastler, BP 20722, 44307 Nantes Cedex 3, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Maurice