ZINDO program

Zemer, M. C. ZINDO Program, University of Florida, Gainesville Florida. 

Substituted cyclopentadienyl ligands can be used to tune the electronic properties of organometallic compounds, as well as the steric bulk of the ligand. For instance, the 1,2,3,4,5-pentamethylcyclopentadienyl ion (Cp ) is used to stabilize the Sc(lll) ion in the electron-deficient Cp 2 cX compound. Molecular orbital calculations using the ZINDO program have shown that there is significant mbdng of the... 

INDO/S Kotzian M, RoschN, Zemer MC (1992) Theor Chim Acta 81 201 (b) ZINDO/S is a version of INDO/S with some modifications, plus the ability to handle transition metals. The Z comes from the name of the late Professor Michael C. Zemer, whose group developed the suite of (mostly semiempirical) programs called ZINDO, which includes ZINDO/S. ZINDO is available from, e.g., Molecular Simulations Inc., San Diego, CA, and CAChe Scientific, Beaverton, OR. INDO and ZINDO are available in some program suites, e.g. Gaussian [55]... 

Zerner, M.C., ZINDO, A General Semi-empirical Program Package. 1990, Quantum Theory Project, University of Florida Gainesville (FI.) USA. 

To simplify the Hartree-Fock problem, Pople introduced CNDO/1 (1965), then CNDO/2 (1967), and then INDO (1967) to yield computer programs that mimic ab initio programs with a minimum of fuss. Jaffe66 improved CNDO to fit spectroscopic absorptions (with a minimum of Cl) this was CNDO/S (1968). Later, Dewar67 introduced MINDO/3 (1975), then MNDO (1977), AMI (1985), and PM3 (1989). For transition metals, Zerner68 introduced ZINDO (1984) these were progressive improvements on INDO, but parameterized to fit thermochemical data, dipole moments, absorption spectra, and so on, to the fitful extent that they are available from experiment. 

Figure 12 Number of publications per year in the CJACS file mentioning semiem-pirical MO programs MOPAC, AMPAC, AMSOL, or ZINDO. The search queries for each curve were (1) mopac, (2) ampac, (3) amsol, and (4) zindo.

Graphical pre- and postprocessor for semiempirical molecular orbital programs extended Hiickel, MOPAC, and ZINDO. Structure building from library of fragments and molecules manipulation. Stick, ball-and-stick, and space-filling display. Orbital, electron density, and electrostatic maps. Reaction energy surfaces. IR and UV spectra. MM2 energy minimization. Dynamics. 

Both ZINDO and molecular mechanics were used as implemented on the Tektronix CAChe workstation. For leading references to ZINDO, a semiempirical program that has been parameterized for the first two rows of transition metals, see (a) MC Zemer, GW Loew, RF Kirchner, UT Mueller-Westerhoff. J Am Chem Soc 102 589-599, 1980. (b) WP Anderson, TR Cundari, RS Drago, MC Zerner. Inorg Chem 29 1-5, 1990. 

In the case of transition metal complexes, the CNDO theory was first applied by Dahl and Ballhausen [24] to MnO,. Their scheme was later extended to INDO by Ziegler [25] and implemented into the general package ODIN [26], Better known is the INDO program ZINDO [27] by M. Zemer and the NDDO implementation due to D.S. Marynick [28]. Both have been applied with some success in transition metal chemistry for structure determination and studies of excited states. Attempts have also been made to extend AMI, PM3 and MNDO to transition metals. All in all it must be said that the methods based on integral approximations have been more prolific in studies of main group compounds than transition metal complexes. The reason for that is likely the considerable extra complexity added by the -orbitals combined with the fact that other attractive schemes are available for d-block compounds. 

The SINDOl program is less generally available than either AMPAC, MOPAC, or ZINDO, but a considerable amount of literature using this method is beginning to appear. The model, as described above, has been parameterized on experimental geometries, binding energies, dipole moments, and ionization potentials. Many comparisons between SINDOl and MINDO/3 and MNDO appear, and we reproduce some of these comparisons in Tables 5 and 6. 

If the reaction path is not obvious, then the most general techniques require information about the second derivatives. There exist, however, several often successful techniques that do not require this. The MOPAC and AMPAC series of programs utilize, for example, the saddlepoint technique, which attempts to approach the transition state from the reactant and product geometry simultaneously. The ZINDO set of models can utilize a combination of augmented Hessian and analytic geometry techniques. This is a very effective method, but unfortunately the augmented Hessian method does require approximate second derivatives and is somewhat time consuming. 

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