Molecular Orbital PACkage

YAcHMOP stands for yet another extended Hiickel molecular orbital package. The package has two main executables and a number of associated utilities. The bind program does molecular and crystal band structure extended Hiickel calculations. The viewkel program is used for displaying results. We tested Version 3.0 of bind and Version 2.0 of viewkel. 

J. J. P. Stewart, MOPAC A General Molecular Orbital Package, Frank J. Seiler Research Laboratory, Colorado Springs, CO, 1987. 

Stewart, J. J. P., MOPAC A general molecular orbital package, QCPE, 455 (1987). 

MOP AC The name means Molecular Orbital Package, but is said to have been inspired by this geographical oddity The original program was written in Austin, Texas. One of the roads in Austin is unusual in that the Missouri-Pacific railway runs down the middle of the road. Since this railway was called the MO-PAC, when names for the program were being considered, MOP AC was an obvious contender (see website). 

A general semiempirical molecular orbital package including parameters for transition metals and for spectroscopy. 

G.A. Landrum, W.V. Glassey, Yet Another Extended Hiickel Molecular Orbital Package (YAeHMOP) (Cornell University Press, Ithaca, 2004). 

The MOPAC (molecular orbital package), which has been explored by Dr. James J.P. Stewart, is the method by which the electron characteristics of a molecule is calculated. The MOPAC determines both an optimum geometry and the electron properties of molecule by solving the Schrodinger equation, using the MINDO/3 [6], MNDO [7], or AMI [8] semi-empirical Hamiltonians developed by M.J.S. Dewar, the MIND-d Hamiltonian developed by W. Thiel, or the PM3 [9] or PM5 semi-empirical Hamiltonians developed by J.J.P. Stewart. 

A general-purpose semiempirical molecular orbital package for the study of chemical structures and reactions A software to visualize structures, predict the properties and behavior of chemical systems, refine structural models, (Molecu lar Simulations Inc.)... 

The AMI (Austin Model 1) Hamiltonian available in Version 3.10 of the MOP AC (Molecular Orbital PACkage) program was used to carry out QM calculations, for the purpose of estimating the partial atomic charges to be used in the electrostatic portion of the potential energy for the calculations on the interactions between pairs of model molecules. [34] The AMI calculations also yielded quantum mechanical estimates of the heats of formation of the model molecules. These heats of formation generally followed similar trends to the MM2 steric energies. 

J. J P. Stewart MOPAC (Version 4.0) A General molecular Orbital Package, Quantum Chemistry Program Exchange (QCPE 455), Department of Chemistry, Indiana University, Bloomington, IN 47405 (1987). 

Tel. 904-392-0541, fax 904-392-8722, e-mail zerner qtp.ulf.edu A general semiempirical molecular orbital package including parameters for transition metals and for spectroscopy. VAX and others. 

MO-LCAO-MNDO method allowed calculation of proton affinities and dipole moment <90Mi 8ii-02>. A MINDO/1 calculation on the ylide (13) predicted more ready addition of DMAD to position 6 than to position 2, thus rationalizing the proportion of pyrrolopyrimidines (14) and (15) formed in cycloaddition (Equation (1)) <86H(24)3473> (see also 8.11.9.2.2). In partly reduced systems, Molecular Orbital Package (MOPAC) heats of formation of pyrrolizine derivatives from pyrrolooxazinone (16) and alkynes <92JA593>, and deprotonation preference in pyrrolopyrazinedione (17) were calculated <79JA1885>. 

The MOPAC program (Molecular Orbital PACkag) (26) Is one of the popular quantum mechanical semiempirical methods. The AM1 (Austin Model 1), developed by Michael Dewar (26), is a generalization of the modified neglect of differential diatomic overlap (MNDO) approximation. Often, AM1 is implemented in the MOPAC, and MOPAC(AMt) has been widely used to minimize molecular conformations, to calculate electronic configuration, and to predict such properties as electron distribution and partial charges. 

MOS-F (Semi-empirical Molecular Orbital Package for Spectroscopy) V4, Fujitsu Limited, 1998. 

MO-S Molecular orbital package used to calculate the spectroscopic properties of a molecule. ... 

Work on correlations of rate coefficients with ionisation potentials for the reactions of NO3 with a series of alkenes has been extended. Ionisation potentials are determined using a semi-empirical molecular orbital package (MOPAC 5.0). We are now able to estimate both room-temperature rate coefficients and Arrhenius parameters for the reaction of NO3 with a wide range of alkenes, including those containing vinylic chlorine atoms (which we earlier found difficult to handle). In an effort to improve our understanding of the physical basis of our observations, ab initio calculations have been performed on a limited number of compounds. Such calculations should overcome some of the limitations of the semi-empirical methods when applied to elements such as chlorine and bromine. 

Landrum GA (1997) Yet another extended Huckel molecular orbital package (YAeHMOP). Cornell University Ithara. http // overlap.chem.cornell.edu 8080/yaehmop.html... 

Alternatively, a simple python script can be downloaded from the Schrodinger Script Center for generating molecular descriptors like topological. Molecular Orbital PACkage (MOPAC) and QuikProp (Script name molecular descriptors.py... 

MOPAC originally released as Dewar s Molecular Orbital PACkage, the program works at the semiempirical level of AMI, PM3 (and later improvements), and RMl. 

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