Relativistic contracted Gaussian-type basis functions for atoms K through Xe

For 36 atoms from K to Xe, compact relativistic Gaussian-type function basis sets are developed in a segmented contraction form: ( 843 2 / 74 / 7 ) for the third row atoms and ( 843 3 / 743 / 74 ) for the fourth row atoms. Spin-free relativistic effects are considered through the third-order Douglas–Kroll approximation. The present basis sets are tested for all-electron calculations of four homo- and 12 heteronuclear diatomics in their ground states. The calculated spectroscopic constants are in good agreement with the experimental values.