- Self-consistent local density electronic structure calculations have been carried out for tungsten and molybdenum in the framework of atomic sphere approximation (ASA) linear muffin-tin orbital (LMTO) method. We have calculated the equation of states and derived the effective interaction potentials for tungsten and molybdenum from the pressure–volume dependence. These potentials were used to calculate the second moment of phonon spectrum, ω2, Debye temperature, and cohesive properties. Moreover, we have also tested the applicability of the effective interaction potentials to calculate the temperature dependence of free energy in liquid tungsten. The obtained thermodynamic functions of solid and liquid phases are employed to determine the melting temperature.