Generally contracted valence-core/valence basis sets for use with relativistic effective core potentials and spin-orbit coupling operators

► gcv-c/v-RECP basis sets give accurate results in DFT, CCSDT and CI calculations. ► SOCI calculations on RuO2+ predict a diamagnetic ground state. ► CASSCF-SD with core/valence polarization correlation effects is needed for InH. ► A 0.3 Å bond length decrease is observed in Cs2 due to 5s/5p subshell relaxation.