A high dispersion study of the OH bands of hydrogen peroxide in the photographic infra-red is described. The rotational structure of the two hybrid bands at 10,283.68 cm^—1 and 10,291.08 cm^—1 is analyzed. The small moment of inertia of hydrogen peroxide is found to be 2.786 × 10^—40 g cm^2 while the harmonic mean of the two larger moments of inertia is found to be approximately 33.9 × 10^—40 g cm^2. The planar cis-configuration is ruled out spectroscopically and it is concluded that hydrogen peroxide exists in a non-planar form. It is tentatively decided that the vibrational levels of hydrogen peroxide are doubled and that the double minimum potential associated with the internal rotation of the OH groups has a high and a low barrie
