All calculations were performed with density functional theory (DFT) using the unrestricted Kohn-Sham formalism (UKS). Calculations on models 1 and 2 were performed for this work and are compared with data on model 3 from a previous publication. The calculations for this work used the ORCA 5.0.3 program suite, whereas Ni, Gallenkamp et al. used the ORCA 4.2.1 program suite. This has implications for some technical settings as well as the trust regions of the predicted Mössbauer parameters as described below.