Dirhodium complexes such as carboxylates and carboxylamidates are very efficient metal catalysts used in the synthesis of pharmaceuticals and agrochemicals. Recent experimental work has indicated that there are significant differences in the isomeric ratios obtained among the possible products when synthesizing these complexes. The relative stabilities of the Rh2(NPhCOCH3)4 tolunitrile complexes, Rh2(NPhCOCH3)4(NCC6H4CH3)2, were determined at the HF/LANL2DZ ECP, 6-31G and DFT/B3LYP/LANL2DZ ECP, 6-31G levels of theory using NWChem 6.3. The LANL2DZ ECP (effective core potential) basis set was used for the rhodium atoms and 6-31G basis set was used for all other atoms. Specifically, the o-tolunitrile, m-tolunitrile, and p-tolunitrile complexes of the 2,2-trans and the 4,0- isomers of Rh2(NPhCOCH3)4 were compared.