Program Isoeff allows to calculate values of isotope effects based on the Bigeleisen equation from quantum-chemical results. Currently results from the following packets are supported: Gaussian, Gamess, Charmm and Mopac. Isoeff can also be used for studies of the influence of small changes of individual elements of Hessian matrix on resulting value of isotope effect.
Most recent releases for Linux (32 and 64-bit) and Windows platforms can be downloaded from this page. The program is provided on the “as is” basis and can contain implementation errors. Although there is no systematic support for the program authors will do their best to remove discovered bugs as soon as possible. The program is available free of charge if its use is acknowledged by providing the reference to the original publication:
„ISOEFF98. A Program for Studies of Isotope Effects Using Hessian Modifications” V. Anisimov, P. Paneth J. Mathem. Chem. 26, 75-86 (1999).