Density Corrected DFT: Dispersion and Dipoles

Density-corrected density functional theory (DC-DFT) targets density-driven errors by substituting the self-consistent density with a “borrowed” density from another calculation. Practically, substituting Hartree Fock (HF) densities can mitigate density-driven errors in a targeted fashion. We present D2C-DFT, an improved parameterization of the D4 dispersion correction specially designed for HF-DFT calculations. D2C-DFT provides more accurate energies for a wide range of molecules and reactions. Benchmarking results on the GMTKN55 database show that D2C-DFT significantly improves results for 6 different semilocal functionals and their hybrids. We also extend the methodology of DC-DFT to the calculation of dipole moments. Analytical results for a model system show that DC-DFT systematically provides a more accurate dipole moment than traditional methods.