we treat this as a molecular property, which we calculate for the isolated molecule. A large λ -has a detrimental effect on the charge mobility due to the exponential decay of charge The electron mobilities for structures with low mobilities are underestimated due to numerical instabilities in the calculation of the transfer integrals, t. A possible correction is discussed in the supporting information. This does not affect the results for the best ranking molecules. transfer rate with respect to λ -. Thus, ignoring the effects of crystal packing, molecules with low λ -are favoured.