The formalism of thermotransport in a binary system is analysed. Focus is put on a detailed consideration of the heat of transport parameter characterizing diffusion driven by a temperature gradient. We introduce the reduced heat of transport parameter Q_{c}^{{}'} , which characterizes part of the interdiffusion flux that is proportional to the temperature gradient. In an isothermal system Q_{c}^{{}'} represents the reduced heat flow (pure heat conduction) consequent upon unit interdiffusion flux. It is demonstrated that Q_{c}^{{*}'} is independent of reference frame and is useful in a practical way for direct comparison of simulation and experimental data from different sources obtained in different reference frames. In the case study of the liquid Ni_{50}Al_{50} alloy, we use equilibrium molecular dynamics simulations in conjunction with the Green–Kubo formalism to evaluate the heat transport properties of the model within the temperature range of 1500–4000 K. Our results predict that in the presence of a temperature gradient Ni tends to diffuse from the cold end to the hot end whilst Al tends to diffuse from the hot end to the cold end.