COMPUTERS & CHEMISTRY An International Journal _____________________________________________________ Contents Vol.19, No. 1, 1995 ______________________________________________________ iii Publisher's Announcement 1 Jonathan D Crane The factorization of buckminsterfullerene into cyclocarbon components 11 Piotr Paneth Theoretical calculations of heavy-atom isotope effects 21 Pierre Hansen and Maolin Zheng Assigning a Kekule structure to a conjugated molecule 27 Istvan Lukovits A note on a formula for the hyper-Weiner index of some trees 33 M Krauss Effective fragment potentials and spectroscopy at enzyme active sites 39 Constantino A Uteras-Diaz, and Jorge Ricardo Letelier A variational-numerical method to solve the one- dimensional wave equation for an arbitrary potential 45 Krystyna Wieczorek-Ciurowa, The use of optimization techniques in the phase identification of sulphation limestone products 51 S Bhattacharjee Geometric volume and new refrigerants-II. Haloethanes Software Note 59 M Sanchez Del Rio, J Chaboy and R Djerbi NPI, A code for EXAFS data analysis Software Review 63 DeLos F DeTar Desk Top Molecular Modeller