Reduced-scaling double hybrid DFT with rapid basis set convergence through localized pair natural orbital F12

Abstract: Following earlier work [Mehta, N.; Martin, J. M. L.; J. Chem. Theory Comput. 2022, 18, acs.jctc.2c00426] that showed how the slow basis set convergence of double hybrid density functional theory can be obviated by the use of F12 explicit correlation in the GLPT2 step (second order G\"orling-Levy perturbation theory), we demonstrate here, for the very large and chemically diverse GMTKN55 benchmark suite, and using the B2GP-PLYP-D3BJ functional as a proof of principle, that the CPU time scaling of this step can be reduced (asymptotically linearized) using the PNO-L (pair natural orbitals, localized) approximation, at negligible cost in accuracy.