The range of validity of QCFF/PI calculations in predicting the vibrational frequencies of the stable C-76 isomer with D-2 symmetry is determined, based on recent experimental results. An excellent correlation was found between the previously reported theoretical data and the recently obtained experimental results for C-76 over the relevant spectral range for the identification of fullerenes. These results show that there is no systematic error in the calculations in the significant region, an assumption that was based on a previous comparison with partial experimental results. (C) 2013 Elsevier B.V. All rights reserved.