Studies of 3D-Ising model with long-range interaction

We use the Monte-Carlo simulations to study thermodynamic properties of Ising models on cubic lattices accounting for interaction with next-nearest neighbors. The results of simulations are in good agreement with an analytic formula that defines the critical inverse temperature as a function of the interaction parameter. The behaviors of the internal energy and the heat capacity indicate that at the critical point the heat capacity has an infinite singularity.