An improved localized molecular-orbital assembler approach for Hartree-Fock calculations of general large molecules

► An improved localized molecular-orbital assembler (LMOA) approach is developed. ► LMOA is developed for the ground-state calculations of general large systems. ► In the present LMOA, each subsystem is placed into background point charges. ► The present LMOA can provide accurate energies for systems with charged groups. ► The energy gradients and geometry optimizations of LMOA are also implemented.