The deformation density and potential have been determined in molecular crystals of tricyclo[4.4.1.01,6]ndeca-2,4,7,9-tetraene-11,11-dicarbonitrile at 150 K from X-ray diffraction measurements. A significant degformation density peak is found near the mid-poind of the the transannular bond. The four short bonds in the annuelene ring acquire slightly more residual density compared to the other bonds