416.gamess
SPEC CPU2006 Benchmark Description

Benchmark Name

416.gamess

Benchmark Author

Gordon Research Group

Department of Chemistry

Iowa State University

Ames, IA 50011

Benchmark Program General Category

Quantum chemical computations

Benchmark Description

A wide range of quantum chemical computations are possible using GAMESS. For a very detailed description, see INTRO.TXT. The benchmark 416.gamess does the following computations for the reference workload:

• Self-consistent field (SCF) computation (type: Restricted Hartree-Fock) of cytosine molecule using the direct SCF method
• SCF computation (type: Restricted open-shell Hartee-Fock) of water and cu2+ using the direct SCF method
• SCF computation (type: Multi-configuration Self-consisted field) of triazolium ion using the direct SCF method

Input Description

For a detailed description of input files, see INPUT.TXT

Output Description

See INTRO.TXT and PROG.TXT

Programming Language

Fortran

Known portability issues

Uses the following features that are either non-standard or deleted in Fortran 95:

• Equivalence of objects of character type with non-character types: The original source makes use of Hollerith constants to load numeric variables. Hollerith constants are deleted from the Fortran 95 standard, although it is supported by most commercial Fortran 95 compilers. To improve portability, SPEC has made source changes to workaround the use of Hollerith constants. This is trigerred by the switch '-DSPEC_CPU_NO_HOLLERITH', which is set by default. With this switch, an alternate source is activated, where character strings are equivalenced with numeric variables, avoiding the use of Holleriths. Unfortunately, equivalencing variables of character type with non-character types is also non-standard in Fortran 95, although it works as expected for most compiler implementations.
• Some formal and actual arguments of subroutines do not have the same data type.
• Some arrays are accessed past the end of the defined array size. This will, however, not cause memory access faults. This happens in the subroutine ALDECI in aldeci.F. An array-bound checker program may return errors due to this standard violation.
• The argument array sizes defined in some subroutines do not match the size of the actual argument passed. This standard violation may cause an array-bound checker program to return errors. This occurs in some subroutines in trans.F, scflib.F and nameio.F

The benchmark 416.gamess source is generated from the original GAMESS by using the 'SEQ' (sequential) directive. So, 416.gamess can only be used for a sequential run and not a parallel run.

References

GAMESS project webpage: http://www.msg.ameslab.gov/GAMESS/GAMESS.html

Introductory Books:

• "Ab Initio Molecular Orbital Theory", W.J.Hehre, L.Radom, J.A.Pople, P.v.R.Schleyer, Wiley and Sons, New York, 1986
• "Modern Quantum Chemistry", A.Szabo, N.S.Ostlund McGraw-Hill, 1989
• "Introduction to Computational Chemistry", F.Jensen Wiley and Sons, Chichester, 1999
• "Introduction to Quantum Mechanics in Chemistry", M.A.Ratner, G.C.Schatz, Prentice Hall, 2000

Computational References:

• GAMESS, M.W.Schmidt, K.K.Baldridge, J.A.Boatz, S.T.Elbert, M.S.Gordon, J.J.Jensen, S.Koseki, N.Matsunaga, K.A.Nguyen, S.Su, T.L.Windus, M.Dupuis, J.A.Montgomery J.Comput.Chem. 14, 1347-1363 (1993)

For more references, please see REFS.TXT

Last updated: 7 March 2006