Development of the orbital-free approach for hetero-atomic systems

The key problem of the orbital-free approach is calculation of kinetic energy, especially for hetero-atomic systems. In this work, we used the mono-atomic functionals of kinetic energy to construct the kinetic functionals of complicated systems. We constructed some atomic weights associated with densities of single atoms and then calculated kinetic functions for some atomic complexes. For the examples of SiC, SiAl, AlC, SiO and CO dimers we have demonstrated possibility of our approach to find equilibrium interatomic distances and dissociation energies for hetero-atomic systems.