In this work the previously developed valence method based on stepwise density matrix approximations has been extended for third row, main group elements (K-Kr). All the approximations have been tested separately in atomic calculations and their contributions to the valence total energies have been presented. Molecular test calculations have been carried out for third row hydrides and chlorides.
Puhakka, E., Hirva, P., & Pakkanen, T. (1995). Molecular valence calculations for third row, main group elements (K-Kr). Journal of Molecular Structure: THEOCHEM, 333(1-2), 79-85. https://doi.org/10.1016/0166-1280(94)03941-D