For the first time the standard formation enthalpy of Bi12.5Nd1.4In0.1ReO24.5 has been determined by solution calorimetry by combining the solution enthalpies of Bi12.5Nd1.4In0.1ReO24.5, 1.4NdCl3 + 0.1InCl30.1InCl3 mixture in 2 M HCl and literature data. The lattice energy for Bi12.5Nd1.4In0.1ReO24.5 has been calculated using Born-Haber cycle. The dependence of lattice energy for Bi12.5R1.5ReO24.5 (R – rare earth element) from radius of rare earth metal was constructed. It was established that dependence was linear and had form: Ulat = −129450 + 45070 rR. Linear character of experimentally obtained dependence was explained using modified variant of Kapustinskii formula obtained by us as following: U = A + BrR.