The maximum principal component of a particular singular value decomposition transformed O h cubic VFZ is ∼65°. The sizes for this first and the remaining 7 dimensions are given in Table . By performing principal component analysis, we find that ∼99.6 % of the variance (spatial dispersion) is explained by the first 5 transformed coordinates of an O h VFZ as shown in Table . What does it mean that the 5th dimension is ∼70 % the size of the 1st dimension? This gives an indication of the shape of the VFZ. The first 5 dimensions contain essentially all of the information, which is consistent with the fact that there should be only 5 independent crystallographic parameters to describe a GB. The fact that these 5 dimensions are of similar size indicates that the VFZ is roughly isometric and can be thought of as a hyper-rectangle or hyper-ellipse with only minor eccentricity.