Diffuse X‐ray scattering by 2,3‐dimethylnaphthalene

The diffuse intensity distribution of X‐rays scattered from a dipolar disordered single crystal of 2,3‐dimethylnaphthalene (2,3‐DMN) has been measured and was found to be nearly independent of temperature in some restricted regions of the reciprocal space. This behaviour was related to a static disorder of the crystal. Lattice parameters were determined between room temperature and 9 K and phase transitions at 227 K and 112 K were observed. The results of the data analysis at 298 K are: the equivalent isotropic displacement parameter U eq for the thermal Debye–Waller factor is (0.18 Å) 2 ; the displacement parameters describing the static disorder are  Å) 2 ,  Å] 2 and  Å] 2 . The molecules show an orientational Gaussian distribution around the x axis with a width of 5.0 (8)°. All these results refer to the molecular inertia system. Correlation coefficients characterizing the mean mutual orientation of neighbouring molecules were determined. The highest correlation coefficient was found along [010]: .