The presence of the disordered nodes raises the question: how are these nodes distributed in space? To answer this question, we need to understand the interactions between the nodes. In our approach, we represent the local configurations with hexapole charge distributions, maintaining their D3h point symmetry [Fig. ]. Based on electrostatic arguments, it is expected that 'antiferro-hexapolar' interactions are favoured between such neighbouring nodes, both along the c-axis and in the ab-plane, as shown in Figure ). Because of the smaller separations as well as the better overlap between the nodes along the c-axis, we expect correlations to be greater along this direction.