For computations on systems involving heavier elements, core electrons are treated by adding the SOC-including pseudopotential of Eq. ( ) and thus by treating solely valence electrons explicitly. An extensive benchmark of SOC-including pseudopotentials is beyond the scope of this work, however, the implementation was validated for the subset of small organic molecules discussed in section 3.1. To enable a straight-forward comparison, computations were performed using aug-QZV2P-GTH basis sets and we therefore restricted the validation to molecules containing solely atoms up to the third row of the periodic table. Overall RMSDs for the comparison of pseudopotential computations against the all-electron reference, given in Table , are smaller than 0.28 eV, respectively. RMSDs in SOMEs are in the range of 10.4-114.5 cm -1 .