  A comparison between theory and experiment, concerning the
K(4s)+K(7s)\rightarrow K(4s)+K(5f) reaction of energy transfer in thermal
collisions, is presented. Relevant cross sections are calculated for the
potassium vapour temperatures in the range of 310-1000 K. They are based on the
theoretical adiabatic K_2 potential energy curves and on the use of the
multicrossing Landau-Zener model. In the temperature range of the present
experiment, 428-451 K, the computed cross sections vary little, from
2.09x10^-14 cm^2 to 2.04x10^-14 cm^2, and agree well with the value
1.8(8)x10^-14 cm^2, which is the average of the corresponding experimental
results.
