Type 3; Large principal distortion with little extra movement AKUSIK -dibenzo-(1,9), (5,11)-bis(acenaphtha)tetracene -www.kingsbury.id.au/AKUSIK.html This diagram represents a compound which is strongly deformed in one dimension (i.e., the Au of C2h, with a huge gap (approx. 2 orders of magnitude) to the other distortions. In this occurrence, the molecule's C2 symmetry is still only approximate, but it would make little sense to refer to it by any other point-group. This is demonstrated by the C2 block which occupies much of the upper right quadrant.