Next, 1177 molecules with storage densities ≥0.54 kJ/g (Figure )) and barriers ≥185 kJ/mol are selected for further refinement using DFT. The lowest energy geometry of DHA and VHF is reoptimized using M06-2X/6-31G(d), which also used to estimate the barrier height using adiabatic scans. Of the 954 molecules for which the DFT calculations succeed, the majority have back reaction barriers that are smaller than the parent molecule. However, one molecule, shown in Table , has a relatively high storage density and barrier height (Figures and) and is subjected to a more thorough DFT investigation.