In a combined approach, density functional theory calculations have been paired to with NMR data to study the mechanism of CO hydrogenation using a cobalt carbonyl catalyst, HCo(CO)₄, as a model system. All stable intermediates in the reaction cycle have been examined allowing for the creation of a potential energy surface. Two different product pathways are possible based upon the insertion of CO leading to either ethylene glycol and methanol or methyl formate and methanol. Previous calculations in the literature have indicated much higher energy paths for these reactions than have been observed experimentally. However, our own examination of this system has revealed significantly better agreement with experiment. The calculations also confirm experimental observations with regard to the nature of the transition state: (CO)₃H₂CoCOH. The results also indicate that (CO)₄CoCOH should be an observable intermediate although experiments have not observed this species to date. Vibrational frequency calculations can be used to evaluate partition functions which can then be used to predict product distributions. New results will more thoroughly examine the influence of ligands such as triethylphosphine (replacing carbonyl groups) upon the product selectivity as well as comparing the performance of HCo(CO)₄ with HMn(CO)₅.