Liquid heat capacities of 33 pure compounds have been calculated using the group contribution equation of state VTPR (volume translated Peng-Robinson). Since the predicted heat capacities were not always in good agreement with the experimental data, systematic investigations were performed to improve the situation. Distinct improvements were obtained by fitting the Twu-alpha-parameters simultaneously to vapor pressure, enthalpy of vaporization and heat capacity data. (c) 2006 Elsevier B.V. All rights reserved.