( 2 Jun 94)
           General Atomic and Molecular Electronic Structure System
                              GAMESS User's Guide
                                as prepared at
                            Department of Chemistry
                             Iowa State University
                                Ames, IA 50011
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              Original program assembled by the staff of the NRCC:
                 M. Dupuis, D. Spangler, and J. J. Wendoloski
               National Resource for Computations in Chemistry
                 Software Catalog, University of California:
                     Berkeley, CA (1980), Program QG01
                   This version of GAMESS is described in
            M.W.Schmidt, K.K.Baldridge, J.A.Boatz, S.T.Elbert,
              M.S.Gordon, J.H.Jensen, S.Koseki, N.Matsunaga,
          K.A.Nguyen, S.J.Su, T.L.Windus, M.Dupuis, J.A.Montgomery
                   J.Comput.Chem.  14, 1347-1363(1993)

                   Section 1 - INTRO.DOC - Overview
                   Section 2 - INPUT.DOC - Input Description
                   Section 3 - TESTS.DOC - Input Examples
                   Section 4 - REFS.DOC  - Further Information
                   Section 5 - PROG.DOC  - Programmer's Reference
                   Section 6 - IRON.DOC  - Hardware Specifics
              Questions about GAMESS may be addressed to:
          Mike Schmidt = mike@si.fi.ameslab.gov = 515-294-9796

          E-mail is much, much, much preferred to phone calls!

              A wide range of quantum chemical computations are
          possible using GAMESS, which
             1. Calculates -RHF-   SCF molecular wavefunctions.
             2. Calculates -UHF-   SCF molecular wavefunctions.
             3. Calculates -ROHF-  SCF molecular wavefunctions.
             4. Calculates -GVB-   SCF molecular wavefunctions.
             5. Calculates -MCSCF- wavefunctions.
             6. Calculates -CI-    wavefunctions using the unitary
                                   group method.
             7. Calculates analytic energy gradients for all these
                wavefunctions except -CI-.
             8. Optimizes molecular geometries using the energy
                gradient, in terms of Cartesian or internal coords.
             9. Searches for potential energy surface saddle points.
            10. Traces the intrinsic reaction path from a saddle
                point to reactants or products.
            11. Computes normal modes, vibrational frequencies, and
                IR intensities.
            12. Computes radiative transition probabilities, and
                spin-orbit coupling constants.
            13. Calculates the second order Moller-Plesset energy
                correction for RHF, UHF, and ROHF wavefunctions.
            14. Obtains localized orbitals by the Foster-Boys,
                Edmiston-Ruedenberg, or Pipek-Mezey methods.
            15. Calculates the following molecular properties:
                   a. dipole, quadrupole, and octupole moments
                   b. electrostatic potential
                   c. electric field and electric field gradients
                   d. electron density and spin density
                   e. Mulliken and Lowdin population analysis
                   f. virial theorem and energy components
                   g. Stone's distributed multipole analysis
            16. Performs semi-empirical MNDO, AM1, or PM3
                calculations for RHF, UHF, or ROHF wavefunctions.
            17. Applies finite electric fields, extracting the
                molecule's linear polarizability, and first and
                second order hyperpolarizabilities.

              A quick summary of the current program capabilities
          is given below.

                      RHF    ROHF    UHF    GVB    MCSCF
                      ---    ----    ---    ---    -----
          Energy      CDP    CDP     CDP    CDP     CDP
           Gradient   CDP    CDP     CDP    CDP     CDP
           Hessian    CDP    CDP     CDP    CDP     CDP
           Hessian    CDP    CDP      -     CDP      -

          MP2         CDP    CD      CD      -       -

          CI          CDP    CDP      -     CDP     CDP

          MOPAC       yes    yes     yes

           C= conventional storage of AO integrals on disk
           D= direct evaluation of AO integrals
           P= parallel execution

                             History of GAMESS
              GAMESS was put together from several existing quantum
          chemistry programs, particularly HONDO, by the staff of
          the National Resources for Computations in Chemistry.  The
          NRCC (1 Oct 77 to 30 Sep 81) project was funded by DOE and
          NSF, and was limited to the field of chemistry.  The NRCC
          staff added new capabilities to GAMESS as well.  Besides
          providing public access to the code on the CDC 7600 at the
          site of the NRCC (the Lawrence Berkeley Laboratory), the
          NRCC made copies of the program source code (for a VAX)
          available to users at other sites.
              This manual is a completely rewritten version of the
          original documentation for GAMESS.  Any errors found in
          this documentation, or the program itself, should not be
          attributed to the original NRCC authors.
              The present version of the program has undergone many
          changes since the NRCC days.  This occured at North Dakota
          State University prior to 1992, and now continues at Iowa
          State University.  A number of persons (some of whom have
          now left the Gordon group) have made contributions:  
          Jerry Boatz, Kim Baldridge, and Shiro Koseki at NDSU; 
          Kiet Nguyen, Jan Jensen, Theresa Windus, Nikita Matsunaga,
          Shujun Su, Brett Bode, and Simon Webb at ISU; 
             Frank Jensen at Odense U.,
             Mariusz Klobukowski at U.Alberta, 
             Henry Kurtz at U.Memphis,
             Brenda Lam at U.Ottawa, 
             John Montgomery at United Technologies, 
             Jeff Schubert at Abbott Labs.
              It would be difficult to overestimate the contributions
          Michel Dupuis has made to this program, both in its original
          form, and since.  This includes the donation of code from
          HONDO 7, and numerous suggestions for other improvements.
              The continued development of this program from 1982 on
          can be directly attributed to the nurturing environment
          provided by Professor Mark Gordon.  Funding for much of the 
          development work on GAMESS is provided by the Air Force 
          Office of Scientific Research. 

              In late 1987, NDSU and IBM reached a Joint Study
          Agreement.  One goal of this JSA was the development of a
          version of GAMESS which is vectorized for the IBM 3090's
          Vector Facility, which was accomplished by the fall of
          1988.  This phase of the JSA led to a program which is
          also considerably faster in scalar mode as well.  The
          second phase of the JSA, which ended in 1990, was to
          enhance GAMESS' scientific capabilities.  These additions
          include analytic hessians, ECPs, MP2, spin-orbit coupling
          and radiative transitions, and so on.   Everyone who
          uses the current version of GAMESS owes thanks to IBM in
          general, and Michel Dupuis of IBM Kingston in particular,
          for their sponsorship of the current version of GAMESS.
              During the first six months of 1990, DEC awarded a
          Innovators Program grant to NDSU.  The purpose of this
          grant was to ensure GAMESS would run on the DECstation,
          and to develop graphical display programs.  As a result,
          the companion programs MOLPLT, PLTORB, DENDIF, and MEPMAP
          were modernized for the X-windows environment, and
          interfaced to GAMESS.  These programs now run on VMS
          VAXstations, Ultrix DECstations, and many other X-windows
          environments as well.   The ability to visualize the
          molecular structures, orbitals, and electrostatic
          potentials is a significant improvement.

              As of July 1, 1992, the development of GAMESS moved
          to Iowa State University at the Ames Laboratory.
              The rest of this section gives more specific credit
          to the sources of various parts of the program.
                                 * * * *
              GAMESS is a synthesis, with many major modifications,
          of several programs.  A large part of the program is from
          HONDO 5.  For sp basis functions, GAUSSIAN76 and GRADSCF
          integrals have been adapted to the HONDO symmetry and
          supermatrix procedure, both for the integral and gradient
              The Direct Inversion in the Iterative Subspace (DIIS)
          convergence procedure was implemented by Brenda Lam (then
          at the University of Houston), for RHF and UHF functions.
              The UHF code was taught to do high spin ROHF by John
          Montgomery at United Technologies, who extended DIIS use
          to ROHF and the one pair GVB case.
              The GVB part is a heavily modified version of GVBONE.

              The CI module is based on Brooks and Schaefer's
          unitary group program which was modified to run within
          GAMESS, using a Davidson eigenvector method written by
          S.T. Elbert.
              The MCSCF part of the program was contributed by
          Michel Dupuis of IBM from the HONDO 7 program.
              Edmiston-Ruedenberg energy localization is done
          with a version of the ALIS program "LOCL", modified
          to run inside GAMESS at NDSU.  Foster-Boys localization
          is based on a highly modified version of QCPE program
          354 by D.Boerth, J.A.Hasmall, and A.Streitweiser.  John
          Montgomery implemented the population localization.
              The numerical force constant computation and normal
          mode analysis was adapted from Komornicki's GRADSCF
          program, with decomposition of normal modes in internal
          coordinates written at NDSU by Jerry Boatz.
              The code for the analytic computation of RHF Hessians
          was contributed by Michel Dupuis of IBM from HONDO 7,
          with open shell CPHF code written at NDSU.  The TCSCF
          CPHF code is the result of a collaboration between NDSU
          and John Montgomery at United Technologies.
              Jon Baker's Newton-Raphson geometry optimization and
          transition state locator was adapted to GAMESS by Frank
          Jensen of Odense University, who has also added the
          restricted step methods of Helgaker and Culot, et al.
          These methods are adapted to use GAMESS symmetry, and 
          Cartesian or internal coordinates.   The non-gradient
          optimization so aptly described as "trudge" was adapted
          from HONDO 7 by Mariusz Klobukowski at U.Alberta, who
          added the capability of CI optimizations to TRUDGE.
              The intrinsic reaction coordinate pathfinder was
          written at North Dakota State University, and modified
          later for new integration methods by Kim Baldridge.
          The Gonzales-Schelegel IRC stepper was incorporated by 
          Shujun Su at Iowa State, based on a pilot code from Frank 
              The radiative transition moment and spin-orbit
          coupling modules were written by Shiro Koseki at North
          Dakota State University.
              The ECP code goes back to Louis Kahn, with gradient
          modifications from IMS in Japan.  The code was adapted to
          HONDO by Stevens, Basch, and Krauss, from whence Kiet
          Nguyen adapted it to GAMESS at NDSU.

              Changes in the manner of entering the basis set, and
          the atomic coordinates (including Z-matrix forms) are
          due to Jan Jensen at North Dakota State University.
              Extension of the 1e- and 2e- integral routines to
          handle spdfg basis sets was done by Theresa Windus at
          North Dakota State University.
              The direct SCF implementation was done at NDSU,
          guided by a pilot code for the RHF case by Frank Jensen.
              The MP2 code for was adapted from HONDO by Nikita
          Matsunaga at Iowa State, who also added the ROHF-MP2
              Incorporation of enough MOPAC version 6 routines to
          run PM3, AM1, and MNDO calculations from within GAMESS
          was done by Jan Jensen at North Dakota State University.
              Implementation of parallel SCF energy and gradient
          calculations by means of the TCGMSG toolkit was done by
          Theresa Windus at North Dakota State University.
              The polarizability calculation by means of finite
          applied fields was implemented by Henry Kurtz of Memphis
          State University.
              The ability to find SCF wavefunctions which exactly
          satisfy the virial theorem was implemented by Frank
          Jensen at Odense University.
              "Point determined charges" were implemented by Mark
          Spackman at the University of New England, Australia.

              The SCRF solvent model was implemented by Dave Garmer
          at CARB, and was adapted to GAMESS by Jan Jensen and
          Simon Webb at Iowa State University.

                             Distribution Policy
              Copies of GAMESS will be provided at no charge, to
          anyone who can reach Mike Schmidt by E-mail, and is not 
          working in a country such as People's Republic of China,
          North Korea, Cuba, and so on.  Your country need not be
          particularly democratic, but it should at least not have
          a governmental policy of driving tanks over students.
              To get a copy, send E-mail to Mike at the following
          E-mail address: 


          and tell what kind of computer you have.  If it happens
          to be an IBM mainframe, be sure to specify whether it
          runs VM, MVS, or AIX.  You will receive GAMESS by E-mail
          as a series of files.  Please be sure that your mailer's
          spool directory contains 10 MB of free disk space *before*
          you ask for GAMESS, so that your incoming mail arrives
                                   * * *
              Persons receiving copies of GAMESS are requested to
          acknowledge that they will not make copies of GAMESS for
          use at other sites, or incorporate any portion of GAMESS
          into any other program, without receiving permission to
          do so from ISU.  This is done by signing and returning
          a straightforward copyright letter.  If you know anyone 
          who wants a copy of GAMESS, please refer them to us for 
          the most up to date version available.
              No large program can ever be guaranteed to be free of
          bugs, and GAMESS is no exception.  If you would like to
          receive an updated version (fewer bugs, and with new
          capabilities) contact Mike over the net.  You should
          probably allow a year or so to pass for enough significant
          changes to accumulate.

                             Input Philosophy
              Input to GAMESS may be in upper or lower case.  There
          are three types of input groups in GAMESS:
              1.  A pseudo-namelist, free format, keyword driven
          group.  Almost all input groups fall into this first
              2.  A free format group which does not use keywords.
          The only examples of this category are $DATA, $ECP,
          $POINTS, and $STONE.
              3.  Formatted data.  This data is never typed by the
          user, but rather is generated in the correct format by
          some earlier GAMESS run.
              All input groups begin with a $ sign in column 2,
          followed by a name identifying that group.  The group name
          should be the only item appearing on the input line for
          any group in category 2 or 3.
              All input groups terminate with a $END.  For any group
          in category 2 and 3, the $END must appear beginning in
          column 2, and thus is the only item on that input line.
              Type 1 groups may have keyword input on the same line
          as the group name, and the $END may appear anywhere.
              Because each group has a unique name, the groups may
          be given in any order desired.  In fact, multiple
          occurences of category 1 groups are permissible.
                                 * * *
              Most of the groups can be omitted if the program
          defaults are adequate.  An exception is $DATA, which is
          always required.  A typical free format $DATA group is
          STO-3G test case for water
          CNV      2
          OXYGEN       8.0
              STO  3
          HYDROGEN     1.0    -0.758       0.0     0.545
              STO  3

              Here, position is important.  For example, the atom
          name must be followed by the nuclear charge and then the
          x,y,z coordinates.  Note that missing values will be read
          as zero, so that the oxygen is placed at the origin.
          The zero Y coordinate must be given for the hydrogen,
          so that the final number is taken as Z.
              The free format scanner code used to read $DATA is
          adapted from the ALIS program, and is described in the
          documentation for the graphics programs which accompany
          GAMESS.  Note that the characters ;>!  mean something
          special to the free format scanner, and so use of these
          characters in $DATA and $ECP should probably be avoided.
              Because the default type of calculation is a single
          point (geometry) closed shell SCF, the $DATA group shown
          is the only input required to do a RHF/STO-3G water
                                 * * *
              As mentioned, the most common type of input is a
          namelist-like, keyword driven, free format group.  These
          groups must begin with the $ sign in column 2, but have no
          further format restrictions.  You are not allowed to
          abbreviate the keywords, or any string value they might
          expect.  They are terminated by a $END string, appearing
          anywhere.  The groups may extend over more than one
          physical card.  In fact, you can give a particular group
          more than once, as multiple occurences will be found and
          processed.  We can rewrite the STO-3G water calculation
          using the keyword groups $CONTRL and $BASIS as
          Cnv    2
          Oxygen       8.0     0.0         0.0     0.0
          Hydrogen     1.0    -0.758       0.0     0.545
              Keywords may expect logical, integer, floating point,
          or string values.  Group names and keywords never exceed 6
          characters.  String values assigned to keywords never
          exceed 8 characters.  Spaces or commas may be used to
          separate items:
              Floating point numbers need not include the decimal,
          and may be given in exponential form, i.e. TIMLIM=30,
          TIMLIM=3.E1, and TIMLIM=3.0D+01 are all equivalent.

              Numerical values follow the FORTRAN variable name
          convention.  All keywords which expect an integer value
          begin with the letters I-N, and all keywords which expect
          a floating point value begin with A-H or O-Z.  String or
          logical keywords may begin with any letter.
              Some keyword variables are actually arrays.  Array
          elements are entered by specifying the desired subscript:
           $SCF NO(1)=1 NO(2)=1 $END
              When contiguous array elements are given this may be
          given in a shorter form:
           $SCF NO(1)=1,1 $END
              When just one value is given to the first element of
          an array, the subscript may be omitted:
           $SCF NO=1 NO(2)=1 $END
              Logical variables can be .TRUE. or .FALSE. or .T.
          or .F.  The periods are required.
              The program rewinds the input file before searching
          for the namelist group it needs.  This means that the
          order in which the namelist groups are given is
          immaterial, and that comment cards may be placed between
          namelist groups.
              Furthermore, the input file is read all the way
          through for each free-form namelist so multiple occurances
          will be processed, although only the LAST occurance of a
          variable will be accepted.  Comment fields within a
          free-form namelist group are turned on and off by an
          exclamation point (!).  Comments may also be placed after
          the $END's of free format namelist groups.  Usually,
          comments are placed in between groups,
          molecule goes here...
              The second $CONTRL is not read, because it does not
          have a blank and a $ in the first two columns.  Here a
          careful user has executed a CHECK job, and is now running
          the real calculation.  The CHECK card is now just a
          comment line.

                                 * * *
              The final form of input is the fixed format group.
          These groups must be given IN CAPITAL LETTERS only!  This
          includes the beginning $NAME and closing $END cards, as
          well as the group contents.  The formatted groups are
          $VEC, $HESS, $GRAD, $DIPDR, and $VIB.  Each of these is
          produced by some earlier GAMESS run, in exactly the
          correct format for reuse.  Thus, the format by which they
          are read is not documented in section 2 of this manual.
                                 * * *
              Each group is described in the Input Description
          section.  Fixed format groups are indicated as such, and
          the conditions for which each group is required and/or
          relevant are stated.
              There are a number of examples of GAMESS input given
          in the Input Examples section of this manual.
                                 * * *
                             Input Checking
              Because some of the data in the input file may not be
          processed until well into a lengthy run, a facility to
          check the validity of the input has been provided.  If
          EXETYP=CHECK is specified in the $CONTRL group, GAMESS
          will run without doing much real work so that all the
          input sections can be executed and the data checked for
          correct syntax and validity to the extent possible.  The
          one-electron integrals are evaluated and the distinct row
          table is generated.  Problems involving insufficient
          memory can be identified at this stage.  To help avoid the
          inadvertent absence of data, which may result in the
          inappropriate use of default values, GAMESS will report
          the absence of any control group it tries to read in CHECK
          mode.  This is of some value in determining which control
          groups are applicable to a particular problem.
              The use of EXETYP=CHECK is HIGHLY recommended for the
          initial execution of a new problem.

                             Program limitations
              GAMESS can use an arbitrary Gaussian basis of spdfg
          type for RUNTYP=ENERGY.  At present, all other RUNTYPs
          are limited to spd basis sets.
              This program is limited to a total of 500 atoms.  The
          total number of symmetry unique shells cannot exceed 1000,
          containing no more than 5000 symmetry unique Gaussian
          primitives.  The total number of contracted basis
          functions (AOs) cannot exceed 2047.  Each contraction can
          contain at most 30 gaussians.  The CI/MCSCF package can
          use at most 255 orbitals.  In practice, you will probably
          run out of CPU or disk before you encounter any of these
              On 32 bit machines such as IBM, VAX, or UNIX the
          number of AOs is limited by the byte packing to just 255,
          rather than the 2047 mentioned above.  An exception is SCF
          runs, using a PK or P integral file, where 361 AOs can be
          used on 32 bit machines.  If your molecule exceeds this
          packing limit, or if you do not have disk space to hold
          the integrals, you can avoid this limit by using the
          direct SCF option.
              Except for these limits, the program is basically
          dimension limitation free.  Memory allocations other
          than these limits are dynamic.

                             Restart Capability
              The program checks for CPU time, and will stop if time
          is running short.  Restart data are printed and punched
          out automatically, so the run can be restarted where it
          left off.
              At present all SCF modules will place the current
          orbitals on the punch file if the maximum number of
          iterations is reached.  These orbitals may be used in
          conjunction with the GUESS=MOREAD option to restart the
          iterations where they quit.  Also, if the TIMLIM option is
          used to specify a time limit just slighlty less than the
          job's batch time limit, GAMESS will halt if there is
          insufficient time to complete another full iteration, and
          the current orbitals will be punched.
              When searching for equilibrium geometries or saddle
          points, if time runs short, or the maximum number of steps
          is exceeded, the updated hessian matrix is punched for
          restart.  Optimization runs can also be restarted with the
          dictionary file.  See $STATPT for details.
              Force constant matrix runs can be restarted from
          cards.  See the $VIB group for details.
              The two electron integrals may be reused.  The
          Newton-Raphson formula tape for MCSCF runs can be saved
          and reused.
                                 * * * *
              The binary file restart options are rarely used, and
          so may not work well (or at all).  Restarts which change
          the card input (adding a partially converged $VEC, or
          updating the coordinates in $DATA, etc.) are far more
          likely to be sucessful than restarts from the DAF file.