DOI: 10.2478/s11534-006-0007-0 Research article CEJP 4(2) 2006 210–222 Translation-rotation coupling and heat transfer in orientationally-disordered phase of CCl 4 Oleg I. Pursky 1∗ , Vyacheslav A. Konstantinov 2† 1 Department of Physics, Technological State University of Cherkasy, 18006 Cherkasy, Ukraine 2 Institute for Low Temperature Physics and Engineering National Academy of Science of Ukraine, 61103 Kharkiv, Ukraine Received 10 August 2005; accepted 22 December 2005 Abstract: The isochoric thermal conductivity of an orientationally-disordered phase of CCl 4 is analysed within a model in which heat is transferred by phonons and above the phonon mobility edge by ”diffusive”modes migrating randomly from site to site. The mobility edge ω 0 is found from the condition that the phonon mean-free path cannot become smaller than half the phonon wavelength. The contributions of phonon-phonon, one-, and two-phonon scattering to the total thermal resistance of solid CCl 4 are calculated under the assumption that the different scattering mechanisms contribute additively. An increase in the isochoric thermal conductivity with temperature is explained by suppression of phonon scattering at rotational excitations due to a decrease in correlation in the rotation of neighbouring molecules. c  Versita Warsaw and Springer-Verlag Berlin Heidelberg. All rights reserved. Keywords: Heat transfer, phonons, ”diffusive” modes, librons PACS (2006): 66.70+f, 63.20.Ls 1 Introduction Theoretical models of heat transfer in solid dielectrics have predicted the thermal conduc- tivity behaviour Λ ∝ 1/T at temperatures T ≥ Θ D (Θ D is the Debye temperature) [1]. However, the thermal conductivity of molecular crystals shows considerable deviations from the above dependence [2–5]. At present, there is no generally accepted theory that ∗ E-mail: pursky o@ukr.net † E-mail: konstantinov@ilt.kharkov.ua