Abstract
The internal rotation of hydrogen peroxide molecule is treated on the assumption that the hindering potential is approximately expressed by the two‐term Fourier expansion: V=(V1/2)(1+cosχ)+(V2/2)(1+cos2χ) . The doublet structure of the infrared absorption spectrum is considered to be caused by the existence of a double minimum in the hindering potential. The available experimental data on the microwave spectra and on the infrared combination bands yield the result of V1=244 cm—1 (700 cal/mole) and V2=319 cm—1 (910 cal/mole). Thus it is concluded that the cis barrier (452 cm—1 or 1290 cal/mole) is definitely higher than the trans one (208 cm—1 or 590 cal/mole).