Cluster approximation for q-dependent correlations in magnetic and ferroelectric systems

cluster calculated by the exact Hamiltonian of the cluster. The constant C is the ratio of the number of nearest neighbors inside the cluster to the total number of nearest neighbors. The method is applied to calculate scattering intensities in potassium-dihydrogen-phosphate-type hydrogen-bonded ferroelectrics. %e find a strong anisotropy in the q… (More)