As listed in Table , most replicates of all motors studied had not progressed to successful photoisomerization by the end of the simulations. Many of these replicates were still in the excited state, but there were also many that hopped to the ground state and fell back to the initial stable form, rather than progressing to the metastable form. These are unproductive replicates, in the sense that they would not lead to rotation of the motor. Quantum yields estimated from the fraction of productive replicates are on the same order of magnitude as reported experimentally for non-MHz alkene motors .