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5HONDO: Ab Initio HFMO Calculations (Version 7.0)

by M. Dupuis, J. D. Watts, H. O. Villar, G.J.B. Hurst, IBM Corporation, Scientific Engineering Computations, Kingston, New York 12401

HONDO is a program for ab initio quantum molecular calculations. The following features are available in the present version of the program:

  1. Calculation of singleÐconfiguration selfÐ consistentÐfield (SCF) wavefunctions (closedÐshell RHF, spinÐunrestricted UHF, restricted openÐshell ROHF), generalized valence bond (GVB) and general multiconfiguration selfÐconsistentÐfield (MCSCF) wavefunctions, and configuration interaction CI wavefunctions.

  2. Calculation of the electron correlation correction to the energy of closedÐshell RHF wavefunctions by means of MO(í)llerÐPlesset (MP) perturbation theory applied to secondÐ, thirdÐ and fourthÐorder levels (with or without the effects of triple excitations).

  3. Full use of molecular symmetry for many wavefunction calculations.

  4. Use of the effective core potential approximation.

  5. Optimization of molecular geometries using the gradient of the energy with respect to nuclear coordinates for all SCF wavefunctions. Optimization can be carried out in the Cartesian space or in the internal coordinate space, with the possibility of freezing some Cartesian or internal coordinates.

  6. Calculation of the forceÐconstant matrix in the Cartesian or internal coordinates space and of the vibrational spectrum (including infrared and Raman intensities) for all SCF wavefunctions.

  7. Calculation of the dipole moment and polarizability with respect to the nuclear coordinates (for use with a previously available forceÐconstant matrix). The forceÐconstant matrix can be transformed to the internal coordinate basis.

  8. Determination of transitionÐstate structures by taking advantage of the energy gradients for all SCF wavefunctions.

  9. Determination of the Instrinsic Reaction Coordinate (IRC) pathway for all SCF wavefunctions.

  10. Molecular energies for several points on a potential energy surface can be calculated in a single run.

  11. NonÐgradient optimization of basisÐfunction exponents. The source code can be modified to carry out optimization of other nonÐlinear parameters, for example, contraction coefficients and even geometrical parameters.

  12. Calculation of the following electronic properties:
    1. dipole moment
    2. quadrupole moment
    3. Mulliken population and bondÐorder and valency analyses
    4. spinÐdensity maps
    5. electrostaticÐpotential maps
    6. localized orbitals via Boys' method
    7. static dipole polarizability
    8. static first and second hyperpolarizabilities.

  13. Representation of an electric field (either uniform or due to point charges).
The program uses Gaussian­type basis functions up to d type. This version of the code can handle up to 50 atoms and 120 shells for a total of 440 unique Gaussian exponential functions. The present version is limited to a maximum of 255 basis functions on byte­oriented hardware and to 512 basis function for word­oriented machines.

Vectorization
The present code is only partially vectorized. Key subroutines call routines available in the IBM Engineering and Scientific Subroutines Library (ESSL). For other routines, compiler directives activate the vectorization of the compiler.

The MP4 module has been developed with vector hardware in mind. It makes extensive use of matrix multiplication routines and performs very well.

Parallelization
No software is provided to run the program in a parallel computer environment. Some FORTRAN statements dealing with parallelization are an integral part of the source code, but additional software is needed. Interested users may contact the authors.

Memory Management
The core is dynamically allocated, depending on the number of basis functions. A common block labelled /SCM/ defines the working area where the data manipulation is done in all the modules which make up the program. If needed, the user can increase or decrease easily the size of the common block /SCM/.

Memory Size Requirements
No overlay directives are provided to link and load the programÐÐthe virtual memory management of the operating system takes over. The source code requires approximately 4 Mb of memory to load, exclusive of the memory required for the common block /SCM/. The size of this common block then determines the total region size for the program. If /SCM/ is 500,000 words long, it occupies 4 Mb. Hence the total region size needed to load HONDO is about 8 Mb.

Restart Capabilities
The program checks for CPU time, can be stopped and restarted where it left off. The restart data are printed and punched automatically.

Technical Details
The program includes a few lines of ASSEMBLY code to get information such as CPU time, time of day and date.

NOTE: Because of the size of this system, it will be distributed on its own magnetic tape.

FORTRAN (IBM / VM or MVS) Lines of Code: 94766


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