[Fe(sIDep) 2 ] +1 ] (3), [(η 6 -C 6 H 6 )FeAr*-3,5-Pr i 2 ] (4) and [(CAAC) 2 Fe] +1 (5) as shown in Figure . Since complex 1 is experimentally characterized with high spin-reversal barrier, it is plumped for benchmarking the methodology. Complexes 2 and 3 are experimentally synthesized and are reported to possess large axial zero field splitting parameter with opposite signs (-62.4 cm -1 for 2 and +34.0 cm -1 for 3) from ab initio DDCI3 calculations. Despite the large values reported for the complexes, both do not possess SIM behavior under any applied fields. We have explicitly studied the electronic structure of these complexes to have a fundamental understanding of this peculiar behavior. We strive to accomplish this by probing their magnetic relaxation pathways. Complexes 4 and 5 are also experimentally synthesized by Ni et al. and Ung et al. respectively. However, to the best of our knowledge, there is no report on the magnetic characteristics of the complexes. Possessing underlying requisites for superior SIMs i.e., linear structure and Fe(I) metal center and hence, unquenched orbital angular momentum, we speculate if the later complexes could manifest themselves as potential contenders for SIMs. Consequently, we have scrutinized the two complexes to investigate their magnetic anisotropy and hence, their potential to act as SIMs.