gam32: User's Manual

    by Ernst J. Schumacher, University of Bern

This is a draft Manual for the use of gamess.32/.64 !

Content of Manual for gam32 script

  1. gam32 script
  2. What is in the gam32 Package
  3. Installation
  4. The Master Menu
  5. The Configuration File
  6. Options in gam321.0
    1. BUILDER
    2. VIEWER
    3. JOB NAME
    4. BUILD
    5. GAMESS INPUT Options
    6. Advanced Options
  7. APPLY
  9. RUN
  11. SAVE
  12. VIEW
  15. References


           gam32 is a 'Dialect'1 GUI to be used in conjunction with GAMESS2. It allows one to build a molecule, save it, run Gamess, and view the structure directly from the output or as a .pdb or .xyz file using free software that can be downloaded off the Internet. By using the 'Configuration File', one can customize the interface to one’s own system. This program stands under the GPL (Gnu Public License). USE AT YOUR OWN RISK. Please report any bugs to me.

The gam32 panels and this Manual have been further developed from the layout of Wayne P. Anderson, J.Chem.Ed 80(2003)968, for PC Gamess, written in Tcl/Tk. However, only 'gamout2pdb.exe' has been copied from Anderson's free archive. It is a FORTRAN binary which produces three output files, 'molecule.pdb', 'molecule.ent' identical to the previous, and ''.

  • I have separated the more general tasks into a Master Menu, external to the main panel. It offers Input, Output and Configuration options in addition to Help and Quitting.
  • Configuration: The calls of external programs conforms to Windows. Carefully note in the template of the configuration file what information needs to be put into the configuration file if you plan to incorporate your own selection of 'Builder' and 'Viewer' tools. 'Molekel', version 4.3 for Windows, and the other builders and viewers should be installed as suggested in the respective packages.

What is in the gam32 Package

          The following parts are necessary for running Gamess with gam32:

(1) gam32 script
gam32.exe compiled script of the next four sources
gam32.d Dialect source code of the main script
gaminp.d Dialect source code of the input script
advan.d Dialect source code of the advanced input script
raspec.d Dialect source code of the IR/Raman spectrum script
grep.exe from Microsoft's UnixTools, searches some of the temporary files
keys.txt keywords for which grep searches an output file (can be edited)

(2) Auxiliary setup
raswin32.exe RasWin molecule viewer

(3) Manuals: The Gamess manuals as PDF files are not included in c:\gamess.32/.64, see below
Manuals.htm this manual with auxiliary files

(4) GAMESS.Windows.32(64).current.msi, not included! See below under Installation how to get and install it..

Installation of gamess.32/.64 and gam32

1) Call this URL, give your e-mail address and select the second item from top:
"GAMESS version October 1, 2010 R3 for Microsoft Windows"
and click on "Submit". If your e-mail address is registered, you'll obtain mail with username, password and a link to download the gamess version of your choice. Currently there are three versions running on Windows platforms:
  • WinGAMESS.current.msi
  • GAMESS.Windows.32.current.msi
  • GAMESS.Windows.64.current.msi
    The last two are the new native Windows builds for this gam32 script. Select the version suitable for your Windows and download it. In the download directory (double) click to unpack and install it, e.g. into c:\gamess.32 or c:\gamess.64.

    2) The script gam32.exe and auxiliary files, content of tables 1 to 3, are extracted from into any directory.

    3) In c:\games.32/.64 run rungms.bat without arguments to see how a gamessjob is properly started.

    4) The following subdirectories (among others) 'tests', 'auxdata', 'scr', and 'tmp' are installed during extraction of the gamess distribution. Two subdirectories are automatically created at the startup of gam32: 'data', and 'output', managed by the script for input and output.

    5) If you install the Gamess Manuals as PDF files in c:\gamess.32(or .64) in a new subdirectory c:\gamess.32(or .64)\Manuals, they can be read by gam32.exe under 'Help' for checking input syntax etc. Gamess PDF-manuals can be downloaded from Gamess documentation.

  • The Master Menu


    Load $VEC group

    This offers the names of the stored \output\*.dat files for you to select the job from which you wish to extract the $VEC group, i.e. the converged orbitals computed in a previous run of the target molecule.


    Load $HESS group

    This offers the names of the stored \output\*.dat files for you to select the job from which you wish to extract the $HESS group, i.e. the matrix of force constants computed in a previous Hessian run of the target molecule. If you set RUNTYP=RAMAN or RUNTYP=VSCF you are prompted to append the $HESS matrix to the input file.



    Recommended termination of gam32. Closes all windows opened during the run, except the display of an IR spectrum which has its own 'Close' button. Of course, you may close any window by clicking into the cross, top right.


    Import *.inp

    Opens the \data directory for you to choose an input file composed elsewhere and put into the \data directory or load an input file of an earlier run. After clicking on the desired name the file is transferred to gamessdir\input and can be viewed and run (perhaps with your edits). Note: The input file may be in UNIX or PC style. However, 'PC Gamess' input files from RUNpcg are not compatible with 'Gamess' input files. If you want to use PC Gamess input you have to eliminate the entry for 'DFTTYP' in the '$CONTRL' group when [View(ing) Input File].



    Opens the \tests directory for you to select one of the test files. After clicking on the desired name the file is transferred to gamessdir\input and can be viewed and run. The input file may be in PC or UNIX format.


    Read *.out

    Opens the \output directory for you to choose an output file of an earlier run. After clicking on the desired name the file is opened in the editor. The buttons [Properties, Show/Print] in the Master Menu and [View Structure] in the main panel become active and let you extract molecular properties or visualize them in the chosen Viewer.


    Read *.dat

    Opens the \output directory for you to choose a .dat file = Gamess PUNCH, of an earlier run. After clicking on the desired name the file is opened in the editor. You can now select and copy $VEC, $HESS, and other groups for pasting into a new application requiring this data. However, in most cases where such an operation is necessary, you are prompted to select an \output\*.dat file. After clicking on the desired filename the extraction of a $VEC or $HESS group is automatically done and written into the input file being created.



    If a job has just been run and gam32 is still active, [Properties, Show/Print] allows to extract a property from the (long!) output file. The property is chosen from a drop-down menu and shown in tabular form in an editor window.
    If no job is active, the \output directory is first opened for you to choose an output file of an earlier run. After clicking on the desired name the property list, as above, is shown for you to choose from. If you select 'Coordinates' as the property, either the input or the optimized coordinates (depending on runtype) are shown and written into a file 'gamess.coo'. From there it can be read into the input of a new job, e.g. to compute the Hessian after an optimization.- The properties may be printed from the editor window in the usual way by clicking [File/Print].


    Conf File

    Opens the 'Configuration File' in the editor to make changes. After editing/saving/closing the editor window the new configuration becomes active. For details, please consult the item 'Configuration File', below.



    Opens this file in the Browser.


    Six pdf files

    Opens one of the chapters of the Gamess US documentation in the pdf reader. It can be searched for keywords etc.



    Shows an URL for checking whether a new version of the script is available.

    The Configuration file

               Many of the parameters in gam32 can be set by the user in the configuration file gam32.ini. A template for this is presented when gam32 is started for the first time. It is opened in the editor for you to adapt it to your system and save it. The most important items are
    1) the path name of the directory where you have installed the gamess.32/.64 distribution, 'C:\gamess.32/.64'.
    2) the correct version of the gamess.32/.64 binary to be used, perhaps '08'.

    The configuration file can later be edited by clicking on 'Configure/Conf File' in the Master Menu. Save changes. You might have to exit and restart gam32 for the changes to take effect.

    The directories of the file editor, the browser, the pdf-Reader, the builders, and the structure viewers must be specified in the Configuration file. Four builders may be defined. Set their call specifications, and the name to be associated with those builders. Similarly, four structure viewers can be specified. The calls for them are to be set and their names specified. If the viewer is capable of reading an output file upon loading, the value of the file extension may be set to, e.g. “pdb” or “out” (for 'Molekel' and 'Molden'). If it is set to “”, no file will automatically be loaded when the viewer is opened. It has to be specified by the usual 'File/Open' dialogue.
               Some of the programs mentioned in this manual have licensing restrictions. Be sure to consult the license agreements before using the programs.
               Although any text file editor that reads large files can be used, I have chosen 'Notepad.exe'. You can choose another, e.g. 'Wordpad.exe', and give the correct calling string. Only for the Configuration file 'Notepad.exe' from Windows has to be used.

    Options in gam32


               The program used to draw and build the molecule is set in gam32.ini. Four builders may be set in the program. For now only one builder is actually installed: ArgusLab.exe4.


               Four viewers may be specified in gam32.ini. If the job is saved, the output structures will be converted to .pdb format with the name ‘jobname’.pdb and in .xyz format with the name ‘jobname’.xyz. gam32 has been tested with gOpenMol10, RasWin12, Molekel13, Jmol15, and Molden16, but other viewers may be used as well. Electron densities and molecular vibrations can be generated in Molekel, gOpenMol, Jmol, and Molden. Files for creating high quality Pov-Ray™14 ray-traced images can be generated in VMD©11. One of the best and time-proven viewers is Molden16 (for Linux and Windows).

    JOB Name

               The name of the JOB must be entered here. The files ‘jobname’.out, ‘jobname’.pdb, ‘jobname’.pun, and ‘jobname’.xyz will be generated in the output directory if the job is saved. The input coordinate file must also have the name ‘jobname’.xxx as specified below. In order to prevent unwanted overwriting of output files, ‘jobname’ here always means the given 'Job Name' plus a four digit number representing the time in hr:min of the start of the computation.- If you [Outputdata/Read *.out] (Master Menu) an earlier run its jobname is automatically placed into the 'Job Name' box.


               The BUILD button calls up the builder specified above. The molecule must be converted to 3D and saved as ‘jobname’.mol, ‘jobname’.ent, ‘jobname’.pdb, or ‘jobname’.xyz in the input directory (specified automatically). A previous GAMESS output file, named ‘jobname’.out, may also be used for coordinate input. In the Master Menu click on [Properties, Show/Print], click on the output file desired and then choose 'Coordinates'. This generates a file 'gamess.coo' which can be read in when composing the input file, choosing 'COO' as Coordinate Type.
    In gam32 input/output files are in separate directories called ./data and ./output.


               The Gamess Input button allows one to set many of the input parameters for gamess, thus defining the nature of the quantumchemical calculation to be performed. The default parameters are set for a simple structure optimization job of a small to medium size, uncharged, singlet molecule. At a minimum the RUNTYP, BASIS, and COORDINATE TYPE will have to be set for each run. A coordinate input file must be in the ./data directory unless it is saved from a previous run in 'gamess.coo' or 'gamess.equ' in the gam32 directory. Coordinates can also be entered manually, see below.

    Some of the GAMESS options require additional input that cannot (yet) be entered through gam32. It is the responsibility of the user to review the input file generated by gam32 and make any additions or changes that are necessary for a successful run. I cannot guarantee that the settings that are placed in the input file will necessarily give a meaningful run. Be sure to read the GAMESS documentation files, particularly INPUT.DOC. A copy of INPUT.DOC is placed in the gam32 directory, and it can be accessed from HELP of the Master Menu. Note that this is the most recent INPUT.DOC from the Gamess-US distribution.

    Summary of GAMESS INPUT Options

    Items in bold - or a red bar on the panel - are the ones that are changed most often.
    Gamess input orders the keywords into "groups", beginning with a "$" in the second position of a new line and ending with " $END". Groups may be given in any order (and even repeated on another line), keywords within groups, too. The following list of groups and their keywords is implemented in the listboxes of gam32. Keywords - parameters of the calculation - may be set by selecting appropriate values in those boxes. There are many more groups and keywords available for more sophisticated jobs, see INPUT.DOC. Names of groups and keywords are not case sensitive. Keywords within a group must be separated by space or newline.



    This is by far the most important entry for any type of quantumchemical computation: The structure of a molecule, i.e. the spacial arrangement of its constituent atoms, determines its energy and most other properties. If not given carefully the whole effort may be meaningless.



    The coordinates are to be entered manually by the user when 'View(ing) Input File'. This is especially necessary if you want to give internal coordinates as Gaussian Z-matrix 'ZMT' or Mopac Z-matrix 'ZMTMPC' format which the script is not able to provide, see 'Input Description' under [Help] in the Master Menu. Notice: I have not provided for the wide variety of Gamess-US input for the names of atoms. The script and its various file manipulations only understand IUPAC atomic symbols. With cartesian coordinates Gamess allows any name for the atoms because their identity is defined by the nuclear charge. gam32 insists on using IUPAC symbols because these are used later for the .pdb and .xyz files to be produced at the end of a job. Furthermore, with ZMT or ZMTMPC coordinates Gamess allows to number the atoms, e.g. C1, C12 or Cu1, Cu19, etc. Please do not use this numbering. In ZMT(MPC) the numbers of the atoms are defined by the (implicit) number of the row in the matrix of structure data on which they appear. However, atomic symbols may be given as
    'Se', 'sE', 'SE' or 'se', and ' C', 'C ', ' c', 'c ', 'C' or 'c'.



    'Equilibrium' (Stationary State) Coordinates are to be read from a file named gamess.equ automatically created with the [SAVE] button or by clicking [Properties, Show/Print] 'Coordinates' in the Master Menu. This file, if it exists, is in the gamessdir directory. It is only created after a successful Optimize run and can be used for subsequent Hessian, and Raman runs. It has the full 10-digit precision of Gamess output. It is not overwritten by a subsequent run, unless this is a successful 'Optimize' run.



    Unique 'Equilibrium' (Stationary State) Coordinates are to be read from a file named gamess.unq automatically created with the [SAVE] button or by clicking [Properties, Show/Print] 'Coordinates' in the Master Menu. This file, if it exists, is in the gamessdir directory. It is only created after a successful Optimize run and can be used for subsequent runs of the same molecule with the same pointgroup symmetry. It has the full 10-digit precision of Gamess output. It is not overwritten by a subsequent run, unless this is a successful 'Optimize' run.



    Coordinates are to be read from a file named gamess.coo automatically created with the [SAVE] button from any run or by clicking [Properties, Show/Print] 'Coordinates' in the Master Menu. This file, if it exists, is in the gamessdir directory. The precision of coordinates is given in the 10-digit format of Gamess, if they are from an 'Optimize' run. In the case of Gamess runs other than 'Optimize' the atomic coordinates are taken from the input (in Bohr, but converted to Angstrom). The precision is given to 8-digits. They may be less precise than what the number of digits indicates, depending on the source of the input.



    Coordinates are to be read from a file in “mol” format named ‘jobname’.mol and is usually produced by one of the molecule builders or read from a chemical databank and saved in the gamessdir\data directory.



    Coordinates are to be read from a file in “pdb” format named ‘jobname’.pdb. PDB files may be exported from several molecule builder programs but also exist in vast numbers in chemical databanks (26319 structures by July 2004). Before using them they have to be deposited in the gamessdir\data directory. With the [SAVE] button the structural data of a successful Gamess run are saved as ‘jobname’.pdb in the .\output directory. If you request coordinates from a PDB file with the jobname given in the main panel of gam32 and gam32 does not find it in the \data directory, the \output directory is opened for you to choose a jobxxxx.pdb file, 'xxxx' being the time stamp of a previous run. Please note: PDB files are in a certain standard PDB format and contain coordinates only to 3-digit precision. Gamesss output coordinates have to be rounded to three digits while being written into a 'jobXXXX.pdb' file.



    These structure files have the identical format of pdb files. They are produced and read by HyperChem named ‘jobname’.ent



    Coordinates are to be read from a file in “xyz” format named ‘jobname’.xyz. This is a format used by Rasmol (RasWin), Chime, and other viewers and is produced with [SAVE] at the end of a Gamess run and saved as ‘jobname’.xyz in the .\output directory. If you request coordinates from an XYZ file to read into an input file and gam32 does not find it as '' in the \data directory, the \output directory is opened for you to choose a file, 'xxxx' being the time stamp of a previous run. The precision of coordinates is given to 8-digits, derived from the 10-digit format of Gamess. In the case of Gamess runs other than 'Optimize' the atomic coordinates are taken from the input (in Bohr, but converted to Angstrom). They may be less precise than what the number of digits indicates.
    The format of XYZ files is not standardized (as is the case for MOL and PDB). The script can read XYZ files form ChemCraft and Ghemical builders, too.



    Indicates the point group symbol that is to be used to build the molecule from symmetry unique coordinates. If the coordinates of all atoms are specified as input cart, choose C1 as the point group. This always works, even if the molecule has a higher symmetry. One disadvantage is, that an optimization run in the C1 group will not produce orbitals (SALC's) and (exact) coordinates reflecting the possibly existing higher symmetry. You may also enter the actual group with all cart coordinates if these accurately transform under the group's symmetry operations. However, a quirk of Gamess, the input generated by Gamess from your input coordinates may break the symmetry and e.g. produce IR/Raman lines violating the selection rules under the full symmetry group. If this should happen, use the equilibrium coordinates of the full group, but choose the group C1 and coord=cart when computing Raman transitions.
    Do not forget to enter a blank line between the point group symbol and the first atom coordinates in the $DATA group unless the symbol is C1 when you must skip that blank line. gam32 does this correctly for you!



    Indicates the order of the principal axis when the point group specification includes an “N”. E.g. for C3v NH3 molecule, select 'Cnv' for GROUP and '3' for NAXIS.




    Indicates that the input file is to be checked for errors.



    Indicates that a full GAMESS run is to be done.



    A single point calculation is to be done at the geometry specified in the input file.



    The geometry of the molecule is to be optimized. If you set HSSEND=.true. in the $STATPT group, see below, the Hessian is computed with the converged coordinates and a normal mode analysis performed as in the next case.



    The force constants and vibrational frequencies in the harmonic approximation are to be calculated at the equilibrium geometry specified in the input file. The intensities for infrared transitions are determined.



    The force constants and vibrational frequencies in the harmonic approximation are to be calculated at the equilibrium geometry specified in the input file. IR- and Raman-intensities are computed. The inclusion of a $HESS group from a previous Hessian run into the input file is mandatory. If the 'RAMAN' keyword is set you are prompted to select a previous output .dat file for extraction of a $HESS group. In case there is none you are alerted. If there are several, the last one with (hopefully) converged force constants is chosen.



    The force constants and vibrational frequencies in an anharmonic approximation are to be calculated at the equilibrium geometry specified in the input file. IR intensities are computed and the coupling between oscillators is treated as well. The inclusion of a $HESS group from a previous Hessian run into the input file is mandatory. If the 'VSCF' keyword is set you are prompted to select a previous output .dat file for extraction of a $HESS group. In case there is none you are alerted. If there are several within the same .dat file, the last one with (hopefully) converged force constants is chosen.- There are more input options, see the keyword $VSCF in [Help/Input Description].



    This new runtype (starting with Gamess 11 APR 2008 (R1)) offers a combination of calculations similar to the same method in Gaussian03 with the aim of obtaining accurate thermochemical quantities as described in L.A.Curtiss et al. JCP 110,4703-4709(1999). Gamess uses a step with CCSD(T), as in L.A.Curtiss et al. CPL 314,101-107(1999), whereas the same step in Gaussian has QCSID(T) model chemistry as in the first publication. Gamess carries the evaluation one step further and gives the expected final result as Std. Enthalpy of Formation ΔHf°(0 and 298) in kcal/mol. Gameix extracts all relevant G3MP2 quantities from the output file and offers the runtype G3MP2 when composing the job such that the requirements of Gamess are fulfilled in the input file. Do not forget to provide adequate memddi by becoming root and typing /sbin/sysctl -w kernel.shmmax=100000000 or more, depending on the size of the job. If you are using gamess.32/.64 instead of Gamess-US do not declare memddi because that is not supported in gamess.32/.64 and you obtain an abort.



    A saddle point location calculation is to be done, see $STATPT for options and Master Menu [Help/Input Description] for details.



    An Intrinsic Reaction Coordinate calculation is to be run, see $IRC in the 'Advanced Options' for fine tuning this calculation type and Master Menu [Help/Input Description] for details.



    NMR shielding tensors (chemical shifts) for closed shell molecules by the GIAO method. The standard defaults are used. These can be finetuned with the help of a $NMR group. See [Help/Input Description] for details.



    Certain specified properties of the molecule at the geometry specified in the input file are to be calculated. This requires some manual editing of the file.



    A restricted Hartree Fock calculation is to be carried out. This option is used for closed shell systems.



    An unrestricted Hartree Fock calculation is to be carried out. This option is generally used for systems containing unpaired electrons and produces separated alpha- and beta-spin orbitals.



    A restricted open shell Hartree Fock calculation is to be carried out. This option is sometimes employed for systems containing unpaired electrons and produces orbitals with paired spins as much as possible.



    No Møller-Plesset perturbation calculation is to be carried out.


    2 [,3,4]

    Electron correlation is included through an MP2, [MP3, MP4] perturbation theory calculation following the Hartree Fock calculation. Please note: Gamess-US only offers MP2! If you need MP3, MP4 (up to the full set) you have to change to PC Gamess, V. 6.4 or later, script RUNpcg.



    Use Cartesian basis functions to construct symmetry-adapted linear combinations (SALC) of basis functions. The SALC space is the linear variation space used. (default)



    Use spherical harmonic functions to create SALC functions, which are then expressed in terms of Cartesian functions. The contaminants are not dropped, hence this option has EXACTLY the same variational space as ISPHER = -1. The only benefit to obtain from this is a population analysis in terms of pure s,p,d,f,g functions which is valuable for teaching purposes.



    Same as ISPHER=0, but the function space is truncated to eliminate all contaminant Cartesian functions [3S(D), 3P(F), 4S(G), and 3D(G)] before constructing the SALC functions. The computation corresponds to the use of a spherical harmonic basis.


    Specifies the overall charge on the system.


    Specifies the multiplicity of the system. This equals n+1, where n is the number of unpaired electrons.



    Effective core potentials (pseudopotentials) are not being used.



    Use the Stevens, Basch, Krauss, Jasien, Cundari ECP’s for the core electrons.



    Use the Hayes-Wadt ECP’s for the core electrons.



    The ECP’s are to be specified in the input file. This option requires manual editing of the input file.


    The maximum number of iterations that are permitted to achieve SCF convergence, default = 30.



    The atom positions are expressed in Cartesian coordinates. This option must be used if the molecule is built with the BUILDERs in gam32.



    Give the coordinates of the symmetry unique atoms only when the point group is specified. The coordinate frame has to be defined in a certain way, see Input Description in the Master Menu [Help]. Cart = unique is Gamess default.



    The coordinates are expressed in the form of a Gaussian Z-matrix. The coordinates must be supplied manually if this option is selected. (Note that this option is not correctly implemented in pcgRUN1.0, since 'ZMAT' instead of 'ZMT' is used as keyword. 'ZMAT' is used as $ZMAT group to define internal coordinates if NZVAR > 0, see Input Description)



    The coordinates are expressed in the form of MOPAC type internals. The coordinates must be supplied manually if this option is selected, see Input Description or any MOPAC manual.



    No Density Functional Calculation is done (default)



    or 30 other DFT functionals may be selected. When right-clicking into the edit box, the list below with a short description of the available functionals pops up. Click on your favorite functional to get it written into the editbox. If you plan to often use DFT in your computations you probably should prefer PC Gamess over Gamess-US. A. A. Granovsky has optimized numerical integration and convergence such that DFT runs about four times faster than with Gamess-US, see the RUNpcg script.
    DFT does not work with the semiempirical Hamiltonians MNDO, AM1, and PM3. If you select one of those, DFTtyp is automatically set to "NONE".
    This is the list of available functionals for grid integration (default); we have not implemented the gridfree method here, see the Input Manual:

      exchange functionals: 
    	SLATER	Slater exchange
    	BECKE	Becke 1988 exchange
    	GILL	Gill 1996 exchange
    	OPTX	Handy-Cohen exchange
    	PW91X	Perdew-Wang 1991 exchange
    	PBEX	Perdew-Burke-Ernzerhof exchange
      pure correlation functionals:
    	VWN	    Vosko-Wilk-Nusair correlation (VWN5)
    	VWN1	Vosko-Wilke-Nusair correlation, RPA params.
    	PZ81	Perdew-Zener 1981 correlation
    	P86	    Perdew 1986 correlation
    	LYP	    Lee-Yang-Parr correlation
    	PW91	Perdew-Wang 1991 correlation
    	PBEC	Perdew-Burke-Ernzerhof correlation
    	OP	    One-parameter Progressive correlation
      exchange/correlation combination functionals:
    	SVWN	SLATER exch. + VWN5 corr.= LDA/LSDA in physics
    	BLYP	BECKE exchange + LYP correlation
    	BOP	    BECKE exchange + OP correlation
    	BP86	BECKE exchange + P86 correlation
    	GVWN	GILL exchange + VWN5 correlation
    	GPW91	GILL exchange + PW91 correlation
    	PBEVWN	PBE exchange + VWN5 correlation
    	PBEOP	PBE exchange + OP correlation
    	PW91PBE	PW91 exchange + PBE correlation
    	OLYP	OPTX exchange + LYP correlation
    	PW91	PW91 exchange + PW91 correlation
    	PBE	    PBE exchange + PBE correlation
      hybrid functionals:
    	BHHLYP	HF and BECKE exchange + LYP correlation
    	B3LYP	Becke + Slater + HF exch. and LYP + VWN5 corr.
    	B3LYP1	use VWN1 in place of VWN5 (as in Gaussian)
    	PBE0	a hybrid made from PBE
    	X3LYP	HF+Slater+Becke88+PW91 exch., LYP+VWN1 corr.



    This gives the maximum time in minutes allowed for the run.


    This selects the maximum number of megawords of memory allowed for the run. One word = 8 bytes. Large jobs will require a larger number than the default. Instead of MWORDS the keyword MEMORY may be given. The unit is word. MEMORY = 1000000 is equivalent to MWORDS = 1.

    [ MEMDDI

    Not provided on the panel, see e.g. the testinput exam36.inp: Some runtypes, especially MPLEVL = 2, require a larger block of memory for communication between the parallel processes than offered by default. This is handled by adding MEMDDI=1 (megaword) in the $SYSTEM group. If you do not include this when the program needs it, you get an abort. With [View Output File] the error is explained and you are advised of the size for MEMDDI to add. Just [View Input File], make the necessary change to the $SYSTEM group by adding a line 'MEMDDI = 1' (or a larger number) and restart the computation. It may be necessary to click on [SAVE] before, to empty the \scratch and \temp directories from intermediate files of the abortive run. ]




    These options are used to specify the basis set. To indicate STO-3G, set GBASIS to STO and NGAUSS to 3. For 3-21G, set GBASIS to N21 and NGAUSS to 3. For 6-31G, set GBASIS to N31 and NGAUSS to 6. Several additional basis set options, including those for use with ECP’s, are given as well. See the 'Input Description'.


    Gives the number of sets of d polarization functions to be added to the heavy atoms. For 6-31G(d), which is often designated as 6-31G*, and for 6-31G(d,p), which is often called 6-31G**, NDFUNC=1 (max. 3).


    Gives the number of sets of f polarization functions to be added to the heavy atoms. NFFUNC=0 or 1.


    The number of sets of p polarization functions to be added to hydrogen atoms. For 6-31G(d,p), NDFUNC=1 and NPFUNC=1 (max. 3).




    A diffuse sp function is included on non-hydrogen atoms in the basis set. This is often used with anions and is designated with a + in the basis set specification. For 6-31+G(d,p), DIFFSP=.TRUE..



    A diffuse s function is included on hydrogen atoms in the basis set. This is often used with anions and is designated with a + in the basis set specification. For 6-31++G(d,p), DIFFSP=.TRUE. and DIFFS=.TRUE..





    Check DAMP to damp oscillations in the energy during SCF iterations. This is often necessary with transition metal complexes.




    Check SHIFT to shift the energies of the virtual orbitals to assist convergence during SCF iterations. This is often necessary with transition metal complexes.



    Direct SCF calculation in RAM. The default (unchecked) is 'conventional' SCF with integrals stored on disk. DIRSCF uses much less disk space and is faster for large numbers of basis functions. For smaller systems conventional SCF is faster. The 'crossover' point is dependent on the kind of computer system and parallelization, if any.


    Gives the SCF convergence limited as 10**(-conv).



    Gives the gradient convergence tolerance in Hartree/Bohr. If this value is changed, the value of NCONV will also have to be adjusted.



    Chooses a positive definite diagonal Hessian as an initial guess



    Reads the Hessian from $HESS. You are prompted to load a $HESS group from a previous Hessian run in a .dat file.



    The initial Hessian is computed. See $FORCE. Additional input may be required.



    If checked, the force constants and vibrational frequencies are calculated at the end of a geometry optimization, if converged. You can then [Show/properties] with added 'Normal Coordinates' and 'Thermochemistry', and generate an [IR Spectrum], similar to a Hessian run.


    Indicates the maximum number of cycles allowed in a geometry optimization, default = 20.


    Selects the optimization algorithm. The default is QA = Quadratic Approximation. You can select NR = straight Newton-Raphson iteration, RFO = Rational Function Optimization, or CONOPT = CONstrained OPTimization. The latter must start from an energy minimum and is used for locating transition states by trying to push the geometry uphill along the mode chosen with IFOLOW, see below. For details see Input Description under 'METHOD'.


    Mode selection switch for RUNTYPE = SADPOINT. The default is 1, meaning that the first, lowest, vibrational 'mode' (rotational and translational degrees removed!) is very likely the reaction coordinate along which the potential energy has a negative curvature. Check the result to be sure that the selection was correct. After a saddle point location run it is recommended to run a Hessian job with the saddle point coordinates. The chosen, and only the chosen mode, usually mode 1, should then possess an imaginary frequency.

    Advanced Options

    Generally these parameters do not have to be changed. Those indicated are set by default without the necessity to click the button for 'Advanced Options'. However, they permit additional control over the calculation, see 'Input Description'. If you set 'Advanced options' different from the default values shown in the boxes, they are made available to the input file after clicking 'Save' on the 'Advanced Options' panel. They do not survive to the input file of your next job, however.





    Specifies whether the final coordinates are to be saved in Molplot format in ‘jobname’.dat. This can be processed by the routines in the GRAPHICS directory of a Gamess Cygwin- or Linux-Installation.




    Specifies whether the final coordinates and wavefunction informations are to be saved in PlotOrb format in ‘jobname’.dat. This can be processed by the routines in the GRAPHICS directory of a Gamess Cygwin- or Linux-Installations.



    Specifies whether information for a Bader Atoms in Molecules input file is saved.



    The default is unchecked and means that the symmetry specified in $DATA is to be used as much as possible in integrals, SCF, gradients etc. If checked, the symmetry in $DATA is only used to build the molecule from unique coordinates, then not used anymore.




    Indicates whether Pople or Hondo integrals are used. See GAMESS documentation.



    Restart control options. "0" defaults to no restart planned. At the end of a Gamess run all files are erased except job.out, job.dat (=Gamess PUNCH file), which are saved to \output, and the input file saved as job.inp to \data.



    Setting restart to "2" prevents some data files to be erased. This allows for SCF restart with 1-, 2-e integrals and MO's saved. There are more options to IREST, see Input Description.



    Controls orbital localization. The default is 'none', skipping localization. A large number of options for finetuning localization is offered when including a $LOCAL group. gam32 does not write a $LOCAL group. You have to compose it along the details given in Input Description.



    Do Foster-Boys localization.



    Do Edmiston-Ruedenberg localization.



    Do Pipek-Mezey population localization.




    number of radial grid points in Euler-Maclaurin quadrature.



    number of angle theta grid points in Gauss-Legendre quadrature.

    [ NPHI


    number of angle phi grid points in Gauss-Legendre quadrature. Automatically assigned as twice NTHE.]




    an (extended) Huckel approximation is to be used to generate the initial MO wavefunctions



    the MO’s are to be read from the $VEC group of a previous calculation. When you are settting 'GUESS=MOREAD' you are asked for an outputfile name from where to append a $VEC group to the input file. In case there is no $VEC group in the selected file you are alerted. If there are several $VEC groups, as usual for Optmize jobs, the last one with (hopefully) converged orbitals is read in. Generally, using the $VEC group from a previous run to start from, is to be preferred compared to the default option 'GUESS=HUCKEL' since the SCF orbitals are of better quality than those from an extended Huckel computation. However, a real gain in computertime is only observable with large jobs.- It is mandatory to give the number of orbitals in NORB, see next item.



    the number of MO’s to be read from a $VEC group when GUESS=MOREAD. You can look at the appended $VEC group when [View(ing) Input File] and write the largest number leftmost of the $VEC table into the NORB variable. There are other choices depending on your job, see the GAMESS Input Description in [Help] in the Master Menu.



    Chooses a positive definite diagonal Hessian as an initial guess



    Reads the Hessian from $HESS. Additional data must be supplied manually.



    The initial Hessian is computed. See $FORCE. Additional input may be required.



    If RUNTYP=IRC this group governs the location of the intrinsic reaction coordinate, a steepest descent path connecting a saddle point to reactants and products. Therefore the prerequisite is a successful saddlepoint location run with RUNTYP=SADPOINT.



    There are five integration methods: The default is GS2, the Gonzalez-Schlegel second order method using BFGS for updating the Hessian. There are more keywords for finetuning GS2, see Input Description. The other four choices for PACE are 'LINEAR', 'QUAD', 'AMPC4', and 'RK4', see Input Description, again.



    If checked the IRC assumes starting from a precise saddle point. In this case the $HESS group of a SADPOINT run has to be attached to the input file. If unchecked, IRC starts from some other point _on_ the IRC path. The safest way is to start IRC from a converged SADPOINT run, check SADDLE, and read the $HESS group by setting HESS='READ' in the $STATPT group.



    This defines in which direction the IRC starts from a saddle point. Default is FORWRD=checked, meaning that the IRC starts in the direction where the largest magnitude component of the imaginary normal mode is positive. You can identify this, if you look up the vibrational amplitudes of the imaginary frequency (normal mode table of the preceding SADPOINT run). If you pick the wrong direction you can always correct this in a second run with the advantage of thus getting an overview of both reaction directions, back to the reactants and forward to the products!



    The number of IRC points to be located in this run, separated by STRIDE.



    Determines how far apart points on the reaction path will be. STRIDE is used to calculate the step taken, according to the PACE method you selected. If you choose the robust method GS2 it can be 0.30 sqrt(amu)-Bohr, for the other methods it should be smaller, 0.1 or even 0.05.



    Maximum number of constrained optimization steps for each IRC point. The default=20 is similar to NSTEP (in $STATPT) pertaining to optimization runs. If an IRC point does not converge, select a larger MXOPT and repeat the run.



    If CITYP=CIS or CITYP=TDDFT this group defines the details. Please consult the instructions, CIS and TDDFT computations are not entirely black-box for significant results and there are more parameters to select differently from the defaults than those offered on the panel. Note that TDDFT (time dependent DFT) often gives better results than CIS with the same basis.



    Number of states to be found (excluding the ground state, so '1' means one excited state). For this number of singly excited states excitation energy and oscillator strength is computed.



    State for which properties and/or gradient (only for CIS) will be calculated. Only one state can be chosen.



    Multiplicity (1 or 3) of the singly excited SAPS (the reference is necessarily single RHF). Only relevant for SAPS based run. SAPS are spin-adapted antisymmetrized products of the desired MULT.



    For CIS only: Type of CI Hamiltonian to use:
    SAPS: spin-adapted antisymmetrized product of the desired MULT will be used (default)
    DETS: determinant based, so both singlets and triplets will be obtained



    For CIS only: Read CIS vectors from a previous computation of the same system, if you want to get other states (default = .false.)



    For CIS only: Omits the first n occupied alpha and beta orbitals from the calculation. The default for n is the number of chemical core orbitals.


              The input file is written with the specified parameters. Until this button is pushed, nothing is written to your hard disk. The file “input” of a previous run is overwritten, but that file has already been saved by 'SAVE' as jobname.inp (including a time stamp) into the \data directory, so nothing is lost (unless you forgot to click 'SAVE', see below)!


               The VIEW INPUT FILE button calls up the required Gamess input file “input” in the editor for checking and, if necessary, editing. The “title” of the run and any special parameters can then be set manually and the file saved before starting a computation.


               The RUN button calls which has all required parameters to call ddikick.x and gamess.XX.x. The 'input' file is presented to gamess for computation. A shell window shows the start and calling string of the run, and announces the termination of the program. If there is an error condition announced by ddIkick there is, usually a comment to guide you to the next steps. If all's well – normal termination – you are prompted to look into the summary.


               The SUMMARY button shows a summary of the run in the Dialect worksheet. It announces whether the run was successful or unsuccessful. If a structure optimization has been run, convergence to a stationary state or failure to do so is announced as well as the final total energy. The output is written to the file .\output\‘jobname’.out.


               The SAVE button generates ‘gamess.coo’ and the two files ‘jobname’.pdb, and ‘jobname’.xyz from either the input coordinates (runtype 'Energy', 'Gradient', Hessian', 'Raman', or an unsuccessful 'Optimize') or the last set of coordinates (successful 'Optimize') of a gamess run. The last two files are saved in the output directory. The equilibrium coordinates of a successful 'Optimize' run are additionally written into a file 'gamess.equ'. If you want to reuse coordinates in a new job with the same name, you can get them from three locations: 'COO', 'PDB', and 'XYZ' see Input Coordinate Type or from 'EQU' and 'UNQ', if you have deposited them from a converged 'Optimize' run. Note that ‘jobname’ contains a four digit time stamp to prevent overwriting files when you use the same job name in a new run. In addition the GAMESS 'PUNCH' file is moved to the output directory as ‘jobname’.dat. In \data a copy of the inputfile is saved as ‘jobname’.inp.

               Essential: Click on [Summary] and [Save] to save the output and clean the system for a new run.


               The VIEW button opens the output file in the editor to study the detailed results. If the run was unsuccessful you find hints on what went wrong. Correct your input accordingly for a new try.


               The VIEW STRUCTURE button calls up the specified viewer. If vfile is set to “pdb” for that viewer, the output structure ‘jobname’.pdb is read into the viewer immediately. If vfile is set to "" in gam32.ini, the viewer is called up, but the user must select the file to be rendered manually. Molekel and Molden are different: They read all the pertinent parts of the output file, render the structure in the opening window and then let you choose any of their features in control menus.


               In order to simulate a spectrum of the fundamental vibrations, the vibrational frequencies and their intensities have to be extracted from the output: From a 'Hessian' run or an 'Optimize' run with HSSEND = true (both are called 'Hessian', here) the Infrared intensities, from a 'Raman' run the IR and Raman intensities (and the depolarization ratios for the latter) are exported. This is done with the help of the Master Menu. There are three cases:

    • If you have a Hessian or Raman run 'on-line', i.e. the job has just been terminated, and gam32 not yet exited, click on [Properties, Show/Print]: You see the drop-down menu of selectable properties. Choose 'Normal Coordinate Analysis'.
    • If you want to look at the vibrations of a previous run [Outputdata/Load *.out] opens the \output directory to select a Hessian or Raman output file. This done click on [Properties, Show/Print]. The drop-down menu of properties opens. Choose 'Normal Coordinate Analysis'.
    • You can click on 'Vibration Spectrum' whereby a drop-down list of all jobname.res files in the \output directory is shown for choosing the Normal Coordinates of a previously saved Hessian or Raman run. The normal coordinates are not shown in this case but the spectrum panel opens and lets you proceed as follows.
    In the first two cases the frequencies, IR-, and, possibly, Raman-intensities are shown in an editor window. This is automatically saved as output\jobname.res for later reuse. Click [Vibrational Spectrum] on the gam32 panel. A list of saved IR/Raman spectra - including the most recent - is opened for you to select one. The spectrum panel opens for you to click on either one of the next two buttons:

    Lin (1/cm)

    this produces a lineplot with an overlay of Lorentzian line shapes on a linear wavenumber scale. It resembles a measured IR spectrum, probably from an FTIR machine, as change in 'transmittance' (blue trace). The Raman bands, if they have been computed, are shown in 'emission' (red trace). The spectral range goes linearly from about 20 to 4200 cm-1.

    Lin (µ)

    this produces a lineplot with an overlay of Lorentzian line shapes in a linear wavelength scale. It resembles a measured IR spectrum from a Rock Salt prism spectrometer as change in 'transmittance' (blue trace). The 'fingerprint' region is better visible than in the first plot but has less detail in the C-H stretch region and the 'skeletal' motions below 666/cm are missing. The Raman bands, from a Raman run, are shown in 'emission' (red trace). The spectral window shown goes from 2.4 - 15 µ (with constant transmission!). Vibrations below about 650 cm-1 are not shown!

    Half Intensity Width (1/cm)

    You may adjust the 'Linewidth' (width of the spectral 'line' at half intensity) to approximate an experiment with varying resolution. Furthermore, the rotational part of a vibration-rotation band is not explicitly simulated. This can be approximately taken care of by adjusting the linewidth.

    Intensity Scale

    This button allows to make weaker IR transitions or Raman emissions visible, or to scale overshooting transitions down. There is no simulation of the transmission behavior of your spectrometer. Assume, that the simulated spectrum has been corrected for experimental shortcomings!

    Scale Frequencies

    It is a sad fact that even the best 'ab initio' computations have problems with the vibrational frequencies in the harmonic approximation. Most calculated frequencies are up to 10% too large, depending on the model chemistry used. This error has been determined over a large sample of calculated versus observed frequencies. It is fairly constant, hence it has become customary to correct calculated spectra by this 'fudge factor'. You can check 'Scale Frequencies' and then select a factor corresponding to your model chemistry. The factors used are published in many locations, e.g. on page 64 of the book 'Exploring Chemistry with Electronic Structure Methods', 2nd ed., by James B. Forseman & Æleen Frisch, ISBN 0-9636768-3-8.
    You can get a better prediction of vibrational frequencies, if you run an anharmonic vibrational analysis using RUNTYP = VSCF and the keyword $VSCF (search for 'VSCF' in Master Menu [Help/Input Description]). However, this takes much more computer time than the harmonic approximation (determining many structure points along each normal coordinate to SCF precision, computing the vibrational eigenfunctions, and taking account of coupling between them). You are prompted to add a $HESS group from a previous Hessian run for starting VSCF. It is recommended to run VSCF only with a good basis set, about 6-31g(d) or better, since minimal basis sets, like STO-3G, often do not produce results that make sense.
    Note: Molekel (version 4.3), Molden and ChemCraft can animate vibrational modes from the "View Structure" button and their own menus. However, Molekel cannot use output from Raman runs whereas Molden and ChemCraft can use IR- and Raman data and also draw a spectrum of both.


    1.        Dialect®


    2.        Gamess

    GAMESS-US: Schmidt, M. W.; Baldridge, K. K.; Boatz, J. A.; Elbert, S. T.; Gordon, M. S.; Jensen, J. H.; Koseki, S.; Matsunaga, N.; Nguyen, K. A.; Su, S. J.; Windus, T. L.; Dupuis, M.; Montgomery, J. A. J. Comput. Chem. 1993, 14, 13471363.
    MacGAMESS: Bode, B. M., Ames Laboratory, Iowa State University, Ames, IA 50011.
    PC GAMESS: Granovsky, A. A., Moscow State University, Moscow, Russia.

    gamess.32/.64 has been compiled with gcc-gfortran from the current version of GAMESS-US ( 11 APR 2008 (R1)), an ab initio quantum chemical package, in a Cygwin environment on Windows.- If you prefer PC GAMESS, another Gamess version for running in the Windows platform, an equivalent script RUNpcg is available. PC-Gamess is several times faster than gamess.32/.64 and runs on multiple CPU's/Nodes. However, it lacks several newer features of current (Win-)Gamess but adds some unique new ones as well.



    3.        NoteTab Lite®


    4.        ArgusLab 4.01© Freeware


    5.        ACD/ChemSketch© Freeware


    6.        ISIS/Draw


    7.        ViewerLite

               Discovery Studio Visualizer/ 

    8.        HyperChem®


    9.        PCModel®


    10.       gOpenMol

    gOpenMol is maintained by Leif Laaksonen, Center for Scientific Computing, Espoo, Finland.


    11.      VMD©

    VMD was developed by the Theoretical Biophysics Group in the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign.

    See Humphrey, W., Dalke, A. and Schulten, K., “VMD - Visual Molecular Dynamics”, J. Molec. Graphics 1996, 14.1, 33-38.


    12.      RasWin 


    13.      Molekel, version 4.3 


    14.      Pov-Ray


    15.      ChemCraft version 1.4 beta, build 237

               Download a 90 day trial version/

    16.      (g)Molden, version 4.6

               download 4.6 for Windows; you need an Xwindows driver

    17.      Ghemical, version 1.02(stable) or 1.90 (dev)


    18.      VB2000, Version 1.8 Rev. 3, now version 2.0 for gamess.32/.64

    VB2000 is developed by Jiabo Li, Brian Duke, and Roy McWeeny, Scinet Technologies, San Diego, CA, 92127, USA: Jiabo Li, and Roy McWeeny, "VB2000: Pushing Valence Bond Theory to New Limits", Int. J. Quantum Chem., 89(2002)208-216