This decision was made because robust large-core ECPs for these elements were unavailable, according to some initial tests. Instead, we chose standard Stuttgart-Cologne small-core ECPs and added semi-core basis functions for the remaining electrons aside from the valence shells. These semi-core functions emulate a larger-core ECP but are not adaptive to the environment, i.e., the second set of coefficients c 1,λ,A is zero for all non-valence functions.