Tackling an accurate description of molecular reactivity with double-hybrid density functionals

Abstract

In this communication, we assess a panel of 18 double-hybrid (DH) density functionals for the modeling of the thermochemistry and kinetics properties of an extended dataset of 449 organic chemistry reactions belonging to the BH9 database. We show that most of DHs provide a statistically robust performance to model barrier height and reaction energies in reaching the `chemical accuracy'. In particular, we show that nonempirical DHs like PBE0-DH and PBE-QIDH, or minimally parameterized alternatives like $\omega$B2PLYP and B2K-PLYP succeed to model accurately both properties in a balanced fashion. We demonstrate however that parameterized approaches like $\omega$B97X-2 or DSD-like DHs are more biased to only one of both properties.