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( 1 Sep 03)
General Atomic and Molecular Electronic Structure System
GAMESS User's Guide
Department of Chemistry
Iowa State University
Ames, IA 50011
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
GGG A M M EEEE SSSS SSSS
G A A MM MM E S S
G GG A A M M M EEE SSS SSS
G G AAAAA M M E S S
GGG A A M M EEEE SSSS SSSS
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)
Another information source is
http://www.msg.ameslab.gov/GAMESS/GAMESS.html
Graphical display of results is possible using MacMolPlt,
a back end visualizer as well as front end input preparer,
available for the MacIntosh computer only. MacMolPlt can
be downloaded freely at the web site just given.
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!
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A wide range of quantum chemical computations are
possible using GAMESS, which
1. Calculates RHF, UHF, ROHF, GVB, or MCSCF self-
consistent field molecular wavefunctions.
2. Calculates CI, MP2, or coupled-cluster corrections to
the energy of these SCF functions.
3. Calculates Density Functional Theory wavefunctions
for RHF, UHF, or ROHF ansatz.
4. Calculates semi-empirical MNDO, AM1, or PM3
RHF, UHF, or ROHF wavefunctions.
5. Calculates analytic energy gradients for all SCF
and DFT wavefunctions, plus closed or open shell
MP2 or closed shell CI.
6. Optimizes molecular geometries using the energy
gradient, in terms of Cartesian or internal coords.
7. Searches for potential energy surface saddle points.
8. Computes the energy hessian, and thus normal modes,
vibrational frequencies, and IR intensities. The
Raman intensities are an optional follow-on job.
9. Obtains anharmonic vibrational frequencies and
intensities (fundamentals or overtones).
10. Traces the intrinsic reaction path from a saddle
point to reactants or products.
11. Traces gradient extremal curves, which may lead from
one stationary point such as a minimum to another,
which might be a saddle point.
12. Follows the dynamic reaction coordinate, a classical
mechanics trajectory on the potential energy surface.
13. Computes radiative transition probabilities.
14. Evaluates spin-orbit coupled wavefunctions.
15. Applies finite electric fields, extracting the
molecule's linear polarizability, and first and
second order hyperpolarizabilities.
16. Evaluates analytic frequency dependent non-linear
optical polarizability properties, for RHF functions.
17. Obtains localized orbitals by the Foster-Boys,
Edmiston-Ruedenberg, or Pipek-Mezey methods, with
optional SCF or MP2 energy analysis of the LMOs.
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18. Calculates the following molecular properties:
a. dipole, quadrupole, and octopole 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
19. Models solvent effects by
a. effective fragment potentials (EFP)
b. polarizable continuum model (PCM)
c. conductor-like screening model (COSMO)
d. self-consistent reaction field (SCRF)
20. When combined with the add-on TINKER molecular
mechanics program, performs Surface IMOMM or
IMOMM QM/MM type simulations. Download from
http://www.msg.ameslab.gov/GAMESS/GAMESS.html
A quick summary of the current program capabilities
is given below.
SCFTYP= RHF ROHF UHF GVB MCSCF
--- ---- --- --- -----
Energy CDP CDP CDP CDP CDP
analytic gradient CDP CDP CDP CDP CDP
numerical Hessian CDP CDP CDP CDP CDP
analytic Hessian CDP CDP - CDP -
CI energy CDP CDP - CDP CDP
CI gradient CD - - - -
MP2 energy CDP CDP CDP - CP
MP2 gradient CDP - CD - -
CC energy CD - - - -
DFT energy CDP CDP CDP - -
DFT gradient CDP CDP CDP - -
MOPAC energy yes yes yes yes -
MOPAC gradient yes yes yes - -
C= conventional storage of AO integrals on disk
D= direct evaluation of AO integrals
P= parallel execution
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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 project (1 Oct 77 to 30 Sep 81) was funded by NSF and
DOE, 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 occurred 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, Paul Day, Brett Bode, Simon Webb, Wei Chen,
Tetsuya Taketsugu, Galina Chaban, Grant Merrill, Graham
Fletcher, Kurt Glaesemann, Dmitri Fedorov, Cheol Choi,
and Rob Bell at ISU; plus
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.
Haruyuki Nakano at U.Tokyo
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, 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.
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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, Digital awarded
a Innovator's 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 under the
Digital Unix or VMS windowing environments, and many other
X-windows environments as well. The ability to visualize
the molecular structures, orbitals, and electrostatic
potentials is a significant improvement.
Parallelization of GAMESS began in 1991, with most
of the work and design strategy done by Theresa Windus.
This multi-year process benefits greatly from the long
term support of GAMESS by the AFOSR, as well as the ARPA
sponsorship of the Touchstone Delta experimental computer.
As of July 1, 1992, the development of GAMESS moved
to Iowa State University at the Ames Laboratory.
The DoD awarded a CHSSI grant to ISU in 1996 to
extend that scalability of existing parallel methods, and
more importantly develop new techniques. This brought
Graham Fletcher on board as a postdoc, and has led to the
introduction of the Distributed Data Interface style of
programming.
The rest of this section gives more specific credit
to the sources of various parts of the program.
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* * * *
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 sp integrals and
Gaussian80 sp gradient integrals are used. Both the sp
rotated axis integrals and the sp gradient packages have
been rewritten in 2001 by Jose Maria Sierra of Synstar
Computer Services in Madrid, Spain.
Rys polynomials are used for any basis functions with
higher angular momentum. Redimensioning of HONDO 1e- and
2e- Rys integral routines to handle spdfg basis sets was
done by Theresa Windus at North Dakota State University.
The current spdfg gradient package consists of HONDO8 code
for higher angular momentum, and was adapted into GAMESS
by Brett Bode at Iowa State University.
The use of quantum fast multipole methods for avoiding
long range integral evaluation in large molecules was
programmed by Cheol Choi at Iowa State and at Kyungpook
National University, and included in GAMESS in 2001.
The ECP code goes back to Louis Kahn, with gradient
modifications originally made by K.Kitaura, S.Obara, and
K.Morokuma at IMS in Japan. The code was adapted to
HONDO by Stevens, Basch, and Krauss, from whence Kiet
Nguyen adapted it to GAMESS at NDSU. Modifications for
f functions were made by Drora Cohen and Brett Bode.
This code was completely rewritten to use spdfg basis sets,
to exploit shell structure during integral evaluation, and
to add the capability of analytic second derivatives by
Brett Bode at ISU in 1997-1998. Jose Sierra of Synstar
removed the last few bugs from this in 2003.
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.
The direct SCF implementation was done at NDSU,
guided by a pilot code for the RHF case by Frank Jensen.
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. Additional GVB-DIIS
cases were programmed by Galina Chaban at ISU.
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The GVB part is a heavily modified version of GVBONE.
The FULLNR and FOCAS MCSCF programs were contributed
by Michel Dupuis from the HONDO program.
The approximate 2nd order SCF was implemented by
Galina Chaban at Iowa State University. SOSCF is
provided for RHF, ROHF, GVB, and MCSCF cases.
The Jacobi 2 by 2 orbital rotation scheme for MCSCF
orbital optimization was written by Joe Ivanic and Klaus
Ruedenberg at Iowa State University in 2001.
The Ames Laboratory determinant full CI code was
written by Joe Ivanic and Klaus Ruedenberg. As befits
code written by an Australian living in Iowa, it was
interfaced to GAMESS during an extremely cordial visit
to Australia National University in January 1998. An
update by Joe in October 2000 exploits Abelian point
group symmetry. A general CI program based on selected
determinants was added by Joe and Klaus in July 2001.
After moving from Ames Laboratory at ISU to the Advanced
Biomedical Computing Center of the National Cancer
Institute-Frederick, Fort Detrick, Joe wrote a determinant
based program for second order CI, in 2002. In early 2003,
Joe added the Occupation Restricted Multiple Active Space
determinant CI program, again written at NCI.
The GUGA CI is based on Brooks and Schaefer's
unitary group program which was modified to run within
GAMESS, using a Davidson eigenvector method written by
Steve Elbert.
Programming of the GUGA analytic CI gradient was done
by Simon Webb in 1996 at Iowa State University.
The CIS gradient program was written in 2003 by Simon
Webb of the Advanced Biomedical Computing Center of the
National Cancer Institute in Frederick.
The sequential MP2 code was adapted from HONDO by
Nikita Matsunaga at Iowa State, who also added the RMP2
open shell option in 1992. The MP2 gradient code is also
from HONDO, and was adapted to GAMESS in 1995 by Simon Webb
and Nikita Matsunaga. In 1996, Simon Webb added the frozen
core gradient option at ISU. The spin-unrestricted MP2
gradient was programmed by Christine Aikens at ISU in 2002.
Haruyuki Nakano from the University of Tokyo interfaced his
multireference MCQDPT code to GAMESS during a 1996 visit to
ISU. Parallelization of the multireference PT code was
done by Hiroaki Umeda at Mie University and included into
GAMESS in 2001.
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The parallel closed shell MP2 code is a descendent of
work for GAMESS-UK by Graham Fletcher, Alistair Rendell,
and Paul Sherwood at Daresbury. This was adapted to GAMESS
at ISU by Graham Fletcher in 1999, after some grief in
developing the necessary DDI infrastructure.
The grid-free DFT energy and gradient code was
written by Kurt Glaesemann at Iowa State University,
starting from the code of Almlof and Zheng, adding four
center overlap integrals, a gradient program, developing
the auxiliary basis option, and adding some functionals.
This was included in GAMESS in 1999.
The grid based DFT program was written in 2001 at the
University of Tokyo, by Takao Tsuneda, Muneaki Kamiya,
Susumu Yanagisawa, and Dmitri Fedorov. Many improvements
such as use of symmetry and initial small grid during the
numerical quadrature, functional development and coding,
and the ability to run in parallel come from this group.
The original program prior to these numerous changes is
from Nevin Oliphant, Hideo Sekino, and Rod Bartlett at QTP.
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.
The numerical force constant computation and normal
mode analysis was adapted from Andy 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. IR intensities
and analytic polarizabilities during hessian runs were
programmed by Simon Webb at ISU.
Code for Raman intensity prediction was written at
Tokyo Metropolitan University in April 2000.
The vibrational SCF and MP2 anharmonic frequency code
for fundamental modes and overtones was written by Galina
Chaban, Joon Jung, and Benny Gerber at U.California-Irvine
and Hebrew University of Jerusalem, and included in GAMESS
in 2000. The solver was modified to perform degenerate
perturbation theory for more accurate results by Nikita
Matsunaga at Long Island University in 2001.
Most geometry search procedures in GAMESS (NR, RFO,
QA, and CONOPT) were developed by Frank Jensen of
Odense University. These methods are adapted to use
GAMESS symmetry, and Cartesian or internal coordinates.
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The non-gradient optimization so aptly described as
"trudge" was adapted from HONDO 7 by Mariusz Klobukowski
at U.Alberta, who added the option for CI optimizations.
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 pilot code from Frank Jensen.
The code for the Dynamic Reaction Coordinate was
developed by Tetsuya Taketsugu at Ochanomizu U. and U.
of Tokyo, and added to GAMESS by him at ISU in 1994.
The two algorithms for tracing gradient extremals
were programmed by Frank Jensen at Odense University.
The program for Monte Carlo generation of trial
structures along with a simulated annealing protocol was
written by Paul Day at Wright-Patterson Air Force Base.
Modifications to this were made by Pradipta Bandyopadhyay
at ISU, and the code was included in 2001.
The surface scanning option was implemented by
Richard Muller at the University of Southern California.
Most polarizability calculations in GAMESS were
implemented by Henry Kurtz of the University of Memphis.
This includes a general numerical differentiation based
on application of finite electric fields, and a fully
analytic calculation of static and frequency dependent
NLO properties for closed shell systems. The latter
code was based on a MOPAC implementation by Prakashan
Korambath at U. Memphis.
Edmiston-Ruedenberg energy localization is done
with a version of the ALIS program "LOCL", modified
at NDSU to run inside GAMESS. 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 LCD SCF decomposition and the MP2 decomposition were
written by Jan Jensen at Iowa State in 1994.
Point Determined Charges were implemented by Mark
Spackman at the University of New England, Australia.
Delocalized internal coordinates were implemented by
Jim Shoemaker at the Air Force Institute of Technology
in 1997, and put online in GAMESS by Cheol Choi at ISU
after further improvements in 1998.
The Morokuma decomposition was implemented by Wei
Chen at Iowa State University.
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The radiative transition moment and Zeff spin-orbit
coupling modules were written by Shiro Koseki at both
North Dakota State University and at Mie University.
The full Breit-Pauli spin-orbit coupling integral
package was written by Thomas Furlani. This code was
incorporated into GAMESS by Dmitri Fedorov at Iowa
State University in 1997, who generalized the spin-orbit
coupling matrix element code generously provided by
Thomas Furlani (restricted to an active space of two
electrons in two orbitals), with assistance from visits
to ISU by Thomas Furlani and Shiro Koseki. Dmitri
Fedorov has since generalized the full two electron
approach to allow for any spins, for more than two spin
multiplicities at a time, and a partial treatment of the
the two electron terms that runs in time similar to the
one electron operator. Space and spin symmetries are
exploited to speed up the runs. Dmitri Fedorov programmed
the SO-MCQDPT options at the University of Tokyo in 2001.
Inclusion of relativistic effects by the Relativistic
scheme of Elimination of Small Components (RESC) method,
was developed by Takahito Nakajima and Kimihiko Hirao at
the University of Tokyo. This code was written by
Takahito Nakajima and consequently adapted into GAMESS
by Dmitri Fedorov, who has extended the methodology in
March 2000 to the computation of gradients. RESC provides
both scalar (spin free) and vector (spin-dependent)
relativistic corrections.
The Normalized Elimination of Small Components (NESC)
was programmed by Dmitri Fedorov at ISU and the University
of Tokyo. Special thanks are due to Kenneth Dyall for his
assistance in providing check values. Extension of NESC
to include gradient computation was also done by Dmitri.
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Development of the EFP method began in the group of
Walt Stevens at NIST's Center for Advanced Research in
Biotechnology (CARB) in 1988. Walt is the originator of
this method, and has provided both guidance and some
financial support to ISU for its continued development.
Mark Gordon's group's participation began in 1989-90 as
discussions during a year Mark spent in the DC area, and
became more serious in 1991 with a visit by Jan Jensen to
CARB. At this time the method worked for the energy, and
gradient with respect to the ab initio nuclei, for one
fragment only. Jan has assisted with most aspects of the
multi-fragment development since. Paul Day at NDSU and
ISU derived and implemented the gradient with respect to
fragments, and programmed EFP geometry optimization. Wei
Chen at ISU debugged many parts of the EFP energy and
gradient, developed the code for following IRCs, improved
geometry searches, and fitted much more accurate repulsive
potentials. Simon Webb at ISU programmed the current
self-consistency process for the induced dipoles. The EFP
method was sufficiently developed, tested, and described
to be released in Sept 1996.
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.
The COSMO model was developed by Andreas Klamt and
Kim Baldridge, at San Diego Supercomputer Center. It was
included into GAMESS by Laura Gregerson in March 2000
during a visit to Ames.
The PCM code originates in the group of Jacopo
Tomasi at the University of Pisa. Benedetta Mennucci
was instrumental in interfacing the PCM code to GAMESS,
in 1997, and answering many technical questions about the
code, the methodology, and the documentation. In 2000,
Benedetta Menucci provided code implementing an improved
IEF solver for the PCM surface charges. This new code was
interfaced to the effective fragment potential method by
Pradipta Bandyopadhyay at Iowa State University in 2000.
The changes to implement iterative solution of the PCM
equations for large molecules, and to provide an accurate
nuclear gradient were carried out by Hui Li and Jan Jensen
at the University of Iowa in 2001-2003, along with the
parallelization.
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The Coupled-Cluster (CC) program included in GAMESS is
due to Piotr Piecuch and Karol Kowalski of Michigan State
University, and Stanislaw A. Kucharski and Monika Musial of
the University of Silesia. In addition to a number of
standard CC methods, including the popular CCSD and CCSD(T)
approaches, the CC codes incorporated in GAMESS are capable
of performing the renormalized and completely renormalized
CCSD[T] and CCSD(T) calculations. This program was
incorporated into GAMESS in May 2002, with the support of
the US-DOE Office of Basic Energy Science's SciDAC
computational chemistry program.
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Distribution Policy
To get a copy, please fill out the application form
available on
http://www.msg.ameslab.gov/GAMESS/GAMESS.html
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.
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Input Philosophy
Input to GAMESS may be in upper or lower case. All
input groups begin with a $ sign in column 2, meaning
exactly column 2 or else it is not detected, followed by
a name identifying that group. 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
category.
2. A free format group which does not use keywords.
The first line of these will contain only the group name,
followed by several lines of positional data usually with
no keywords, and a last line containing " $END" only.
The only members of this category are $DATA, $ECP, $MCP,
$GCILST, $POINTS, $STONE, and the EFP related data $EFRAG,
$FRAGNAME, $FRGRPL, and $DAMPGS.
3. Formatted data. This data is NEVER typed by the
user, but rather is generated in the correct format by
some earlier GAMESS run. Like catagory 2, the first line
contains only the group name, and the last line is a
separate $END 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
occurrences 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
$DATA
STO-3G test case for water
CNV 2
OXYGEN 8.0
STO 3
HYDROGEN 1.0 -0.758 0.0 0.545
STO 3
$END
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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
calculation.
* * *
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 occurrences will be found and
processed. We can rewrite the STO-3G water calculation
using the keyword groups $CONTRL and $BASIS as
$CONTRL SCFTYP=RHF RUNTYP=ENERGY $END
$BASIS GBASIS=STO NGAUSS=3 $END
$DATA
STO-3G TEST CASE FOR WATER
Cnv 2
Oxygen 8.0 0.0 0.0 0.0
Hydrogen 1.0 -0.758 0.0 0.545
$END
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:
$CONTRL MULT=3 SCFTYP=UHF,TIMLIM=30.0 $END
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.
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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 occurrences
will be processed, although only the LAST occurrence 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,
$CONTRL SCFTYP=RHF RUNTYP=GRADIENT $END
--$CONTRL EXETYP=CHECK $END
$DATA
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.
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* * *
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.
1
Program limitations
GAMESS can use an arbitrary Gaussian basis of spdfg
type for computation of the energy or gradient. Some
restrictions apply, for example, analytic hessians are
limited to spd basis sets.
This program is limited to a total of 500 atoms. The
total number of shells cannot exceed 1000, containing no
more than 5000 symmetry unique Gaussian primitives. Each
contraction can contain no more than 30 gaussians. The
total number of contracted basis functions, or AOs, cannot
exceed 2047. You may use up to 50 effective fragments, of
at most 5 types, containing up to 100 expansion points.
In practice, you will probably run out of CPU or disk
before you encounter any of these limitations. See Section
5 of this manual for information about changing any of
these limits, or minimizing program memory use.
Except for these limits, the program is basically
dimension limitation free. Memory allocations other
than these limits are dynamic.
1
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.