Extended Data Fig. 3: Illustration of projecting a (111) plane along [112] and [110] beam directions.

V−Co(Ni) as the nearest neighbour is assumed in this idealized model to be the prevailing CSRO. The numbers 1, 3 and 4 indicate the 1st, 3rd and 4th nearest neighbours, respectively, around a centre atom C. a, Plan view of a close-packed (111) plane, projected along the [112] beam direction. The distance between the nearest points in the [110] direction is r* (compare with Fig. 3d). b, Plan view of the same (111) plane, observed along the [110] beam direction. Unlike for the [112] beam direction, when projected along the [110] beam direction (for example, horizontal dashed lines) the centre atom will be directly superimposed onto two unlike 1st neighbours. This mixed column, when compared with the case in a (no overlapping of unlike species in the column) blurs the difference (and hence the contrast) from the neighbouring columns. [112] is therefore the preferred beam direction to see the CSRO of interest.