1,2-Difluorohydrazine represents a model for studying short-range discriminative interactions between two chiral radicals. Possible diastereomeric structures of the system were theoretically investigated by means of nonempirical SCF quantum chemical calculations. Four minima and six saddle points separating them were found on the potential energy surface. All the stable structures and one transition complex were completely optimized. Thermodynamic properties for the equilibrium between the two most stable conformers (meso and chiral) of difluorohydrazine are as follows (in kJ/mol): [Formula: see text], [Formula: see text] (standard state: ideal gas at 101.325 kPa, 298 K).