Figure correlates the graphene plane angle with the average p z contribution to the iron-d-orbitals. The orbital data used to calculate the admixtures and the resulting standard deviations are shown in Table . In the fully planar 1, only the d xz and d yz orbitals can mix with the π system since the d xy , d z 2 and d x 2 -y 2 orbitals have zero overlap with the carbon p z orbitals. The small model 2 is visually non-planar, quantified here at ca. 19°. Accordingly, more admixture of p z character into the d xy , d z 2 and d x 2 -y 2 orbitals is found, while less mixing with the d xz and d yz orbitals is possible. As described above, the increased model 2 Large is more planar, and thus the admixture of p z character into the d manifold is comparable to that of 1. For the convex model 3, similar amounts of p z character are found as for the small model 2. Although expanding this model increases its non-planarity, which should lead to worse overlap of the π system with the d xz and d yz orbitals, the admixture is found to increase. Similarly, a small decrease in p z character in the d xy , d z 2 and d x 2 -y 2 orbitals is found. We attribute these changes to the larger π-system, where more orbitals can participate in the conjugation.