For the dual node set up, the S 1 gradient (computed on node 2) will not have a ground state orbital file, since it is the first job that is computed on this node. As evident in Figure , the average S 1 gradient job time using 2 nodes is indeed larger than that of the equivalent S 1 gradient job using only one compute node. Likewise, the S 2 gradient (computed on node 1) does not have the excited state coefficient file since the previous gradient job on the same node was only for the S 0 state, also leading to a larger job time in Figure compared to the single node setup. Nevertheless, a performance gain of 153% was observed when using two compute nodes over just one. We expect that the relative performance gains using 2 nodes should get closer to the 200% limit when more than two excited states are involved, such as we describe below for the zinc-phthalocyanine and fullerene charge transfer system.