Temperature dependence of the rigid-body motion of anthraquinone

Anthraquinone has been studied at five temperatures between 296 and 162 K. The unsatisfactory agreement factors obtained in earlier studies probably resulted from the use of data collected from twinned crystals; needle-like crystals with approximately equidimensional cross sections are usually contact twins related by reflection across (10 (2) over bar). The temperature dependence of the T and L tensors is normal. The out-of-plane displacement parameters of the O atom indicate a large-amplitude internal vibration.