For the first time the standard formation enthalpy of Bi2.5Nd1.4In0.1ReO24.5 has been determined by solution calorimetry by combining the solution enthalpies of Bi2.5Nd1.4In0.1ReO24.5, 1.4NdCl(3) + 0.1InCl(3)0.1InCl(3) mixture in 2 M HCl and literature data. The lattice energy for Bi2.5Nd1.4In0.1ReO24.5 has been calculated using Born Haber cycle. The dependence of lattice energy for Bi2.5Nd1.4In0.1ReO24.5 (R - rare earth element) from radius of rare earth metal was constructed. It was established that dependence was linear and had form: U-lat = -129450 + 45070 r(R). Linear character of experimentally obtained dependence was explained using modified variant of Kapustinskii formula obtained by us as following: U = A + Br-R.