Hartree-Fock is commonly used to calculate the electron-electron interaction energy. The core idea of this theory is the average field approximation, which applies to the overall effect of an electron by other electrons that an equivalent field can represent. Unlike DFT, the Hartree-Fock method only considers the exchange of energy between electrons and electrons. At Alfa Chemistry, we use the Hartree-Fock approach to complete the ELF calculation via accurate non-local exchange and hybrid functionals. Electron Localization Function Prediction https://wavefunction.alfa-chemistry.com/services/electron-localization-function-prediction.html