|
217. OPTMO: A Molecular Orbital Program for Locating
Equilibrium Geometries Employing the MINDO/2 or the
Extended Hckel Methods
by Andrew Komornicki and James McIver, Department of Chemistry, State University of New York, Buffalo, New York 14214 OPTMO is a multipurpose program written to provide equilibrium geometries and energies on a variety of molecular systems. The program has provisions to work within either the MINDO/2 or the Extended Hckel framework. Depending on the options chosen, the user may request either one function evaluation or a series of function evaluations which will lead to the equilibrium geometry predicted by the method employed. A function evaluation involves the calculation of the energy and the gradient for a particular molecular geometry. The program has been written in such a way as to provide maximum efficiency with the minimum amount of user input. The MINDO/2 portion is based on the work of Dewar and coworkers, and the parameterization employed is from the original papers. The Extended Hckel method of Hoffmann has also been taken from the original references, as have the empirical parameters. Since within the past few years Hoffmann has advocated the use of a hydrogen exponent of 1.3 rather than 1.0, this has also been implemented. In its present form, the MINDO/2 method includes parameters for the atoms of carbon, hydrogen, oxygen, and nitrogen. The Extended Hckel method is parameterized for hydrogen, boron, carbon, and nitrogen. FORTRAN IV (CDC 6400) Lines of Code: 1941 Recommended Citation: A Komornicki and J. McIver, QCPE 11, 217, (1972). |