The electronic structure and chemical bonding properties of CeRh2Sb2 are provided based on ab initio DFT calculations of the two model forms. The energy results show a stabilization of simple tetragonal ST versus body centered tetragonal BCT. Chemical bonding indicating the strongest interactions within the Rh-Sb substructure in both forms also shows two types of anti-bonding interactions involving antimony (Sb-Sb and Sb-Rh) in BCT. This could be at the origin of the instability of the Sb substructure which becomes defective as observed experimentally. It is also significant for the destabilization of BCT versus ST which presents more bonding like interactions. (C) 2012 Elsevier B.V. All rights reserved.