Results for the structure parameters of A are given in Tables IV. We started by considering the gas phase results. A gas phase optimisation at the PBE-D3/def2-TZVP level confirms the previous findings, showing a bending of the Cp hydrogens (5.0°on average) away from the cation. However, the situation greatly changes once the environment is included. Already at the one-body level the inversion of the hydrogen bending can be observed. As in the experimental structure (1.6°on average), all Cp hydrogens bend towards the cation (by 2.3° on average). Adding two-body corrections at the same level of theory reduces the overall bending. The final values are underestimated but closer to experiment. This again highlights the impact of many-body corrections in the structural properties. The charge accumulation on the ring side facing the complexed cation is partly due to the repulsion caused by the nitrogens of a neighboring unit contacting the other side. Part of this interaction is due to the nitrogen lone pairs which are, of course, best described by QM methods.