On the development of a gold-standard potential energy surface for the OH- + CH3I reaction.

We report a story where CCSD(T) breaks down at certain geometries of the potential energy surface (PES) of the OH- + CH3I reaction. To solve this problem, we combine CCSD-F12b and Brueckner-type BCCD(T) methods to develop a full-dimensional analytical PES providing method- and basis-converged statistically-accurate SN2 and proton-transfer cross sections.