title: Scrutinizing "Invisible" astatine: A challenge for modern density functionals.
abstract: The main-group 6p elements did not receive much attention in the development of recent density functionals. In many cases it is still difficult to choose among the modern ones a relevant functional for various applications. Here, we illustrate the case of astatine species (At, Z = 85) and we report the first, and quite complete, benchmark study on several properties concerning such species. Insights on geometries, transition energies and thermodynamic properties of a set of 19 astatine species, for which reference experimental or theoretical data has been reported, are obtained with relativistic (two-component) density functional theory calculations. An extensive set of widely used functionals is employed. The hybrid meta-generalized gradient approximation (meta-GGA) PW6B95 functional is overall the best choice. It is worth noting that the range-separated HSE06 functional as well as the old and very popular B3LYP and PBE0 hybrid-GGAs appear to perform quite well too. Moreover, we found that astatine chemistry in solution can accurately be predicted using implicit solvent models, provided that specific parameters are used to build At cavities. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Laboratoire SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université De Nantes, 4 Rue Alfred Kastler, BP 20722, Nantes Cedex 3, 44307, France.|Laboratoire CEISAM, UMR CNRS 6230, Université De Nantes, 2 Rue De La Houssinière, BP 92208, Nantes Cedex 3, 44322, France.
authors.forename: Dumitru-Claudiu
authors.initials: DC
authors.lastname: Sergentu
authors.affiliation: Laboratoire CEISAM, UMR CNRS 6230, Université De Nantes, 2 Rue De La Houssinière, BP 92208, Nantes Cedex 3, 44322, France.
authors.forename: Grégoire
authors.initials: G
authors.lastname: David
authors.affiliation: Laboratoire SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université De Nantes, 4 Rue Alfred Kastler, BP 20722, Nantes Cedex 3, 44307, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Montavon
authors.affiliation: Laboratoire SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université De Nantes, 4 Rue Alfred Kastler, BP 20722, Nantes Cedex 3, 44307, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Maurice
authors.affiliation: Laboratoire CEISAM, UMR CNRS 6230, Université De Nantes, 2 Rue De La Houssinière, BP 92208, Nantes Cedex 3, 44322, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Galland
keywords: astatine; benchmark; density functional theory; equilibrium constants; spin-orbit coupling