Orientational order parameter and mean square displacement of solid heavy nitrogen in the low-temperature phase. Experimental data

This work presents the results of the analysis of the temperature dependence of the x-ray reflection intensity from solid heavy nitrogen in the ordered phase. The temperature dependence of the behavior of the orientational order parameter and mean square displacement of ¹⁵N₂ molecules obtained from x-ray data is plotted. Based on the dependencies obtained, the orientational order parameter was determined at 0 K, which is 12% higher than the orientational order parameter obtained in theoretical works. It was found that the heavy nitrogen molecule “freely” rotates in the crystal at temperatures above 45 K.