Lattice Theory of Fourth‐Order Elastic Constants of Primitive Lattices. Application

The lattice theory of fourth‐order elastic constants for primitive lattices recently derived by Goyal and Kumar is applied to obtain the relations for the FOE constants of CsCl structure type solids within the framework of the Lundqvist many‐body potential. The derived relations of FOEC are used to compute the numerical values of the FOE constants and the second‐order pressure derivatives of the SOE constants of cesium halide solids.