  The calculation of the elastic scattering properties of mixtures composed by
rubidium and potassium atoms is reported and compared with experimental results
in detail. The improved potentials for both molecular states the singlet and
the triplet of the RbK are presented, and the scattering lengths a_{t} and the
effective range r_{e} are calculated with the help of this potential using WKB
and Numerov methods for Rb-K in the triplet and singlet state. In addition, the
convergence of these scattering properties as the depending on a K_{0}
parameter is investigated using Quantum Defect Theory. The evaporative cooling
other results that include the cross section and the spin-charge cross section,
the rate coefficient as a function of the energy and the ultra-low temperature
are also presented in this study.
