The generalized valence bond method is extended for use in electronic structure calculations of two‐atomic molecules made up of the heavy atoms. By applying a purely numerical Hartree–Fock (HF) or Dirac–Hartree–Fock (DHF) basis set, we were able to efficiently produce the potential curves for a large range of the interatomic distances. The configuration interaction and nonorthogonal basis sets are used to obtain an accurate solution for the realistic molecular systems. Adaptation for parallelism allows the simulation to be partitioned and carried out on the coupled multiprocessor network (SP‐2) at the NIST. Calculations have been performed for Na₂ and In₂ quasi‐molecules in excited states. © 1995 John Wiley & Sons, Inc.