Results for geometry optimisiations of the individual states for Cz-AQ are presented in (Figure ). At the S 0 minimum, we find similar state characters as in vacuo (Figure , centre) only that, again, the ππ * states are somewhat reduced in energy altering the overall state ordering. Once again, we find excellent agreement between the bright S 2 state obtained at 2.97 eV using the ptSS scheme and the experimental absorption maximum of 2.91 eV. Unlike Cz-BDT, there are notable differences in the energies and state characters at the individual geometries, which also agrees well with the fact that the geometries obtained (see Table ) are quite different to each other. Crucially, we find for the TDDFT optimised S 1 geometry that the S 1 state becomes bright and has a significant amount of charge transfer character (red) along with an enhanced exciton size of 7.99 Å (SS-PCM). We propose to interpret this phenomenon in the context of excited-state symmetry breaking: The S 1 state is Laporte forbidden at the ground state geometry due to its approximate inversion symmetry but this restriction is lifted once the symmetry is broken in the excited state as one half of the molecule planarises (see Table ). To represent the symmetry breaking, we use the linear electron-hole separation (d he , Eq. ( )). This value vanishes for symmetric charge transfer systems but approaches the value of d exc in the idealised case where charge is transferred from one donor to one acceptor, both represented as point charges. As expected, d he is zero for the symmetric S 0 -optimised geometries. In the case of S 1 , by contrast, we find that for all the ππ * states d he differs strongly from zero reaching half of d exc or more. This highlights that symmetry breaking of the geometry does indeed also localise the excited states.