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GAMESS-UK

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This application note has been generated by extracting information from Parts 1,2 and 16 of the GAMESS-UK manual That manual was developed by Martyn Guest and a number of colleagues at Daresbury Laboratory.

The user who wishes to acquire rapid familiarity and a sufficient subset of knowledge to use the program, albeit perhaps in a somewhat restricted fashion, should concentrate on the first two parts (Part 1, Part 2) together with the appropriate machine specific examples of Part 16.

Introduction to GAMESS-UK

GAMESS-UK is a general purpose ab initio molecular electronic structure program for performing SCF- and MCSCF-gradient calculations, together with a variety of techniques for post Hartree Fock calculations.

The program is derived from the original GAMESS code, obtained from Michel Dupuis in 1981 (then at the National Resource for Computational Chemistry, NRCC), and has been extensively modified and enhanced over the past decade. This work has included contributions from numerous authors, and has been conducted largely at the former EPSRC (Engineering and Physical Sciences Research Council), and now CCLRC Daresbury Laboratory, under the auspices of Collaborative Computational Project No. 1 (CCP1). Other major sources that have assisted in the on-going development and support of the program include various academic funding agencies in the Netherlands, and ICI plc.

All publications resulting from use of this program must include the following acknowledgement:

GAMESS-UK is a package of ab initio programs. See: "http://www.cfs.dl.ac.uk/gamess-uk/index.shtml",
M.F. Guest, I. J. Bush, H.J.J. van Dam, P. Sherwood, J.M.H. Thomas, J.H. van Lenthe, R.W.A Havenith, J. Kendrick, "The GAMESS-UK electronic structure package: algorithms, developments and applications",Molecular Physics, Vol. 103, No. 6-8, 719-747.

The package is derived from the original GAMESS code due to M. Dupuis, D. Spangler and J. Wendoloski, NRCC Software Catalog, Vol. 1, Program No. QG01 (GAMESS), 1980.

General Features

GAMESS-UK is a general purpose ab initio molecular electronic structure program for performing SCF- and MCSCF-gradient calculations, together with a variety of techniques for post Hartree Fock calculations. On-going development of the code is co-ordinated from Daresbury, with the program currently available on a wide range of machines.

The program utilises the Rys Polynomial or Rotation techniques to evaluate repulsion integrals over s,p,d,f and g type Cartesian Gaussian orbitals. Open- and closed-shell SCF treatments are available within both the RHF and UHF framework, with convergence controls provided through a hybrid scheme of level shifters and the DIIS method. In addition generalised valence bond, complete active space SCF and more general MCSCF, and Møller-Plesset (MP2 and MP3) calculations may be performed. The most recent additions to the code, available within Version 7.0, include a full-featured Density Functional Theory (DFT) module, with access to a wide variety of functionals (S-VWN, B-LYP, B3-LYP etc). This module was developed under the auspices of CCP1.

The analytic energy gradient is available for each class of wavefunction above. Gradients for s and p Gaussians are evaluated using the algorithm due to Schlegel, while gradients involving d,f and g Gaussians utilise the Rys Polynomial Method. Geometry optimisation is performed using a quasi-Newton rank-2 update method, while transition state location is available through either a synchronous transit, trust region or `hill-walking' method. Force constants may be evaluated analytically and by numerical differentiation; coupled Hartree-Fock (CHF) calculations provide for a range of molecular properties, including polarisabilities and molecular hyperpolarisabilities and, through the calculation of dipole moment and polarisability derivatives, the computation of infra-red and Raman intensities.

Ab initio core potentials are provided in both semi-local and non-local formalism for valence-only molecular orbital treatments.

Conventional CI (using the table-driven selection algorithms within the framework of MR-DCI calculations), Direct-CI and Full-CI correlation treatments are available. Both CCSD and CCSD(T) coupled-cluster calculations are available for closed-shell systems.

The direct calculation of molecular valence ionization energies may be performed though Green's function techniques, using either the outer-valence Green's function (OVGF) or the two-particle-hole Tamm-Dancoff method (2ph-TDA) .

Calculations of electronic transition energies and corresponding oscillator strengths may also be performed using either the Random Phase Approximation (RPA) method or the Multiconfigurational Linear Response (MCLR) procedure. The RPA calculations may be performed either within the conventional approach where the two-electron integrals are transformed or with a ``direct'' implementation.

A variety of wavefunction analysis methods are provided, including population analysis and distributed multipole analysis , localised orbitals, graphical analysis and calculation of 1-electron properties.

The restriction of a maximum of 255 basis functions when performing conventional processing of two-electron integrals has been removed in many of the modules in Version 7.0 of the code. The program structure is open-ended in both direct-SCF and direct-MP2 mode, so that direct-SCF calculations up to 12000 basis functions have been performed. Version 7.0 also features a significant extension to the parallel capabilities of GAMESS-UK.

In addition to the functionality outlined above, the program includes a Utilities module concerned with house-keeping, library file creation, file manipulation etc.

Areas of application for GAMESS-UK include:

Using GAMESS-UK on the HPCx system

Only licensed users may access GAMESS-UK. If you are not a licensed user and wish to use GAMESS-UK please contact the HPCx help desk. This information is a short extract from Part 16 of the User's Guide and Reference Manual. Please consult the manual for full details.

Choice of job parameters

The number of nodes allocated is of course dependent on both the type of calculation to be undertaken, and size of molecule under study. Recommended node allocations for typical SCF and MP2 calculations as a function of basis set size are given in the ``Illustrative Examples'' section below, as are elapsed timings as a function of node count for a number of typical calculations.

Job Submission on the HPCx system

GAMESS-UK is compiled as a single executable file, gamess-uk. The program expects to find the input in a file called datain. The GAMESS-UK binaries and examples on HPCx can all be found in the directory:

/usr/local/packages/gamessuk/

The examples for the different versions of GAMESS-UK are in the directory:

/usr/local/packages/gamessuk/examples

There are example submission scripts for submitting Global Array (ga) and MPI jobs in the directory:

/usr/local/packages/gamessuk/examples/LL_scripts

Further Information

The User's Guide and Reference Manual is now divided in sixteen parts or `chapters' and the parts may be broadly classified as follows:

Parts 12-15 comprise a series of machine specific examples using the code. In Part 12 we present a sequence of worked examples on a range of UNIX machines, including the HP Model 9000/755, PentiumPRO under Linux, Cray C90 (under UNICOS) and other workstations, both interactively, and using the specially provided script rungamess (Part 13). Execution under VM/CMS on the IBM 3090 is described in Part 14. while details of running under OpenVMS (on the DEC alpha) are provided in Part 15.

Acknowledgements

HPCx records its thanks to Martyn Guest, Daresbury Laboratory for permission to extract parts of the GAMESS-UK manual to make this application note.

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