In the 7S+3T calculations, out of the 61 remaining ESDs in ECIS, there are 37 with M S = 0 and 12 each with M S = ±1. After spin adaptation, we obtain 25 singlet ES-CFs (consisting of 25 ESDs with M S = 0) and 12 triplet ECSFs (consisting of 12 ESDs with M S = 1). In ECISD, out of the 1411 ESDs, 631 have M S = 0, 336×2 have M S = ±1, and 54×2 have M S = ±2. Spin adaptation then produces 295 singlet ECSFs (consisting of 403 ESDs with M S = 0) and 282 triplet ECSFs (consisting of 336 ESDs with M S = 1), as well as 54 quintet ECSFs (consisting of 54 ESDs with M S = 2) which are not used here. On the other hand, in the 8S+3T calculations, slightly more ESDs and ECSFs were obtained, as given in the table. Note that in ECISD, the spin adaptation of ESDs having M S = 0 does not only produce singlet ECSFs, but also triplet and quintet ones, which could in principle be used to calculate triplet/quintet states with M S = 0. Similarly, the spin adaptation of ESDs with M S = 1 yields some quintet ECSFs. However, as discussed, it is sufficient to calculate states of only one M S value for each multiplicity and hence these higher-spin ECSFs are discarded.