Previous work scored only on single reaction steps of the catalytic cycle . This proved to be somewhat effective. The GA did improve upon reaction energies used in the scoring function, at the cost of the introduction of significant barriers at other parts of the catalytic cycle. As such, in this work it was decided to include both types of charge-transfer in the scoring function by selecting the intermediates involved in the first charge (H + + e -) transfers (N 2 , N 2 H + , N 2 H). Reaction energies are therefore obtained for the first protonation and first reduction of the N 2 moiety. We denote the protonation reaction energy as E p and the reduction energy as E r and these reactions are seen in equations ( ) and (3). The shorthand form Mo N x H y is used as a label for the whole molybdenum plus ligand complex for a specific intermediate. The energies for proton and electron donors are also calculated with GFN2.