INDO is a semi-empirical quantum mechanical program written by Professor Michael C. Zerner and his colleagues at the University of Guelph in Canada, and the University of Florida at Gainesville. BIOSYM Technologies sells ZINDO (discount for academics!) and a user interface (InsightII). Users get access to the BIOSYM response center and we market the latest version from Zerner's group who is contracted with us to send his latest innovations. ZINDO produces the usual sort of output, such as energy levels, molecular orbitals, energies of formation, population analyses, dipole moment, atomic charges, etc, and is parameterized for the first 30 elements, bromine and iodine, and the second row transition metals. The version we presently offer can handle up to 250 atoms. BIOSYM's ZINDO offers three SCF types, Restricted Hartree-Fock, Unrestricted Hartree-Fock, and Restricted Open-shell Hartree-Fock which allows one to model compounds containing transition metal elements. There is a wide range of calculation methods available (Extended Huckel, Iterative Extended Huckel, CNDO/1 and 2, INDO/1 and 2, PPP, etc) and ZINDO performs single point energy calculations, optimization calculations (to give ground or transition states), CI spectra to model uv-vis spectra (singlets, doublets, etc., Rumer general CI, GUGA CI, Frequency calculations (to characterize the optimized geometry) and Frequency Optimization calculations (to Optimize and then do a Frequency calculation). BIOSYM's ZINDO drives our eigenvector following optimizer which allows the location of both ground states and transition states and the user may specify ANY desired combination of distance, angle, or dihedral constraints, as well as frozen atoms. This is quite useful for preventing annoying phosphine ligand inversion during an otherwise routine optimization! Dummy atoms may be defined to help with the application of constraints. Along with this are options to calculate non-linear optical properties alpha, beta and gamma (static and frequency dependant). NLO properties arise from the polarization induced in a material by an intense electric field, which arises from the orientationally averaged sum of the induced polarizations of individual molecules. The user can apply a static electric field, point charges, and vary the strength and frequency of the field used during the NLO calculation. BIOSYM's ZINDO contains the Kirkwood Onsager's self-consistent reaction field model for mimicking the effect of solvation, which is particulary useful for predicting the effects of solvation on stucture and on uv-vis spectra, and offers both spherical and elliptical cavity shapes. If you'd like a free trial contact Julie Bryant here at BIOSYM. Julie Bryant BIOSYM Technologies, Inc. Phone: 619/597-9707 9685 Scranton Road Fax: 619/597-9777 San Diego, CA 92121 E-Mail: julie@biosym.com USA Regards to all, Dr. Max Muir ----