Extending Density-Corrected Density Functional Theory to Large Molecular Systems

Practical density-corrected density functional theory (DC-DFT) calculations rely on Hartree-Fock (HF) densities, which can be computationally expensive for systems with over a hundred atoms. We extend the applicability of HF-DFT using the dual-basis method, where the density matrix from a smaller basis set is used to estimate the HF solution on a larger basis set. Benchmarks on many systems, including the GMTKN55 database for main-group chemistry, and the L7 and S6L datasets for large molecular systems demonstrate the efficacy of our approach. We apply the dual-basis method to both DNA and HIV systems, and compare with the literature. A careful reparameterisation of HF-r2SCAN-DC4 eliminates the negative s8 coefficient, with no loss of performance.