Electrostatic energy and anion ordering in monoclinic ScOF

The electrostatic energy for each of the three possible anion configurations consistent with the structural data for monoclinic scandium oxyfluoride has been calculated by the Ewald method. The results support the conclusion of Holmberg obtained from X-ray data as to the actual anion array. In terms of the Born model the calculated values explain why one particular array is favoured over the others.