Adiabatic Connection Correlation Functionals in Metallic Solids from Hartree-Fock Gaussian Basis Set Ground-State

Adiabatic Connection Integrand Interpolation (ACII) methods, which mix the second- order perturbation theory correlation with density functionals from the strong interac- tion regime, have been successfully applied to molecular systems, strongly correlated systems as well as the uniform electron gas (UEG). Here, we consider real metal- lic solids, including transition metals. We tested different ACII approaches, with in- creased accuracy in reproducing the UEG correlation, and with different strong interac- tion functionals within the Point-charge-plus-Continuum (PC) model. Calculations are based on the Hartree-Fock (HF) ground state, which has been obtained with Gaussian Type Orbital basis set, properly reoptimized towards the HF global minimum, with a derivative-free approach. We compare different metallic properties such as lattice constants, cohesive energies and bulk total correlation energies with accurate reference results. We found that only the ACII approach with high accuracy for the UEG and with the strong interaction functional reproducing the exact PC model for the Wigner crystal yields a correct second-order gradient-expansion correlation coefficient. This allows reproducing lattice constants and bulk correlation energies with an accuracy comparable to the best state-of-the-art approaches.