Valence‐bond calculations have been carried out on ZnO and HgO using a basis set of Slatertype atomic orbitals and the one‐ and two‐electron integrals as computed in the semiempirical AM1 molecular orbital method. The zero differential overlap approximation has been used to calculate integrals between atomic orbital Slater determinants using the rules for matrix elements between determinants formed by orthogonal orbitals. Diabatic and adiabatic curves have been analyzed for the two systems, and results compared with molecular orbital AM1 results. © 1992 John Wiley & Sons, Inc. Copyright © 1992 John Wiley & Sons, Inc.