We calculate the polarizabilities of TCNE along different molecular axes using densityfunctional perturbation theory as implemented in FHI-aims (see Methods Section for details). The results are visualized in Figure . We find that TCNE exhibits a large polarizability in the π-plane. We obtain a polarizability of 127 a 0 3 in the direction of the C --C bond (x-axis in Figure ) and 122 a 0 3 in the molecular axis perpendicular to the C --C bond (y-axis in Figure ). The polarizability perpendicular to the π-plane (z-axis in Figure ) is only about 40 % of this value, 47 a 0 3 . Since the polarizability is directly related to the change of the energy in an electric field, it follows from these values that TCNE molecules in gas phase will preferentially align with the π-plane parallel to the field.