Hello everyone, In addition to the Excel file posted by Jordi Delago, there is a web utility that computes stable isotope fractionations online. The compilation comprises now more than 450 pairs of isotopic species in the sytems of H, C, O, S. The user interface has also been updated since the original posting in early January. The program computes the 1000 ln alpha value from the selceted equation and input temperature. The 1000 ln alpha value is returned with the equation coefficients and the reference (s). The program uses a general formulation: 1000 ln alpha = A (10^18/T^6) + B (10^12/T^4) + C (10^9/T^3) + D (10^6/T^2) + E (10^3/T) + F The URL for the Isotope Fractionation Calculator(IFC) is: http://www.ggl.ulaval.ca/cgi-bin/isotope/generisotope.cgi The database for the IFC program is also an Excel file that could be made available easily either as a posting on the IFC or ISOGEOCHEM pages. Because the IFC is updated regularly following suggestions from stable isotope geochemsits, the datafile will have to be updated regularly. Good day everybody! Dr. Georges Beaudoin, Ph.D. Professeur agrégé Directeur du programme de géologie Équipe MEDEF Département de géologie et de génie géologique Université Laval Québec, Qc Canada G1K 7P4 tel. 418-656-3141 fax. 418-656-7339 Visitez ma page WEB http://www.ggl.ulaval.ca/personnel/beaudoin/Georges.Beaudoin.html ou celle de notre équipe de recherche, le MEDEF http://www.ggl.ulaval.ca/personnel/medef/index.html