Original sentence: It uses the formula:-.The Davidson correction is a simple correction that is often applied in calculations using the method of configuration interaction, which is one of several post-Hartree-Fock ab initio quantum chemistry methods in the field of computational chemistry.and  are the energies of the CISD and Hartree-Fock wavefunctions respectively.is an estimate of the correction required to estimate , the energy of the CISDTQ wavefunction.is the coefficient of the Hartree-Fock wavefunction in the CISD expansion
Edited sentence: It uses the formula.The Davidson correction is a simple correction that is often applied in calculations using the method of configuration interaction, which is one of several post-Hartree–Fock ab initio quantum chemistry methods in the field of computational chemistry.where a0 is the coefficient of the Hartree–Fock wavefunction in the CISD expansion, ECISD and EHF are the energies of the CISD and Hartree–Fock wavefunctions respectively, and ΔEQ is the correction to estimate ECISDTQ, the energy of the CISDTQ wavefunction