The role of the exchange in the embedding electrostatic potential for the fragment molecular orbital method

Abstract

We have examined the role of the exchange in describing the electrostatic potential in the fragment molecular orbital method and showed that it should be included in the total Fock matrix to obtain an accurate one-electron spectrum; however, adding it to the Fock matrices of individual fragments and pairs leads to very large errors. For the error analysis we have used the virial theorem; numerical tests have been performed for solvated phenol at the Hartree-Fock level with the 6-31 G* and 6-311 G* basis sets. © 2009 American Institute of Physics.