Describing transition metal homogeneous catalysis using the random phase approximation

Abstract

The performance of the direct random phase approximation (RPA) method based on a Kohn–Sham reference for transition metal chemistry is studied by making comparison to (dispersion-corrected) density functional theory (DFT) and (spin-scaled) Moller–Plesset theory. The recently developed local-pair coupled-cluster method DLPNO-CCSD(T) is used as a benchmark. Emphasis is placed on the study of complete realistic mechanisms and reactions involving large systems. Electronic energies for the mechanism of C–H and C–C bond activation by rhodium fragments are presented as well as for ruthenium-catalyzed olefin metathesis. In addition, the WCCR10 test set, which comprises ten reactions, is revisited, and reaction energies for the reaction of a $$\mu $$ -chloride-bridged palladacyclic dimer with phosphane ligands are presented. RPA yields results that are on average within 2–3 kcal/mol of the theoretical benchmark with a maximum deviation of 5 kcal/mol. Of the methods studied, RPA behaves most systematically and is able to provide results of similar accuracy to dispersion-corrected functionals. RPA can thus serve as a complementary method to DFT to obtain insight into transition metal chemistry. Attention is paid to the basis set convergence behavior of RPA as well.