The geometrical structures and optical emission spectra of the K(5S)Xe-N polyatomic exciplexes are calculated as functions of temperature in the range from 1 to 200 K. The relationships between the emission spectra and the thermal properties are investigated by use of the Metropolis Monte Carlo method. The peak energy values and the linewidths of the transition energy of the calculated emission light spectra of individual exciplexes reflect the structure and the thermal properties of each polyatomic exciplex. As the result of a detailed examination of relationships between the geometrical structure and the optical emission spectra of the KXe3, KXe7, KXe8, and KXe9 polyatomic exciplexes, a change in the structure of a given polyatomic exciplex, or the dissociation into a smaller cluster, can be detected by the discontinuities in the peak energy of the emission light and the linewidth as functions of temperature.