• The main outlier is the state visually assigned as d (doughnut). Fig. shows NTOs for that state. Although visually the state appears to be localized on the CaO-group, the CTNs analysis shows that a significant portion of the electronic density is ascribed to the AB fragment. A similar observation about the analogous B 2 Σ + state of SrOH was made in the previous study, where a significant contribution to the state was attributed to hydrogen's s orbital .