General Description

This documentation contains some general information on how to compile and run the POTFIT program. It also details the various calculation types the program offers.

This program package calculates the MCTDH-adapted natural potential representation of an analytically given potential energy surface. The separable and relevant region iteration procedure are included. See the PhD-thesis of Andreas Jäckle and the MCTDH review for further details.

The multi-dimensional potential energy surface to be represented as a natural potential expansion must be a member of the MCTDH operator-functions library opfuncs.

The interface to the MCTDH-package is defined via the natpot data file created by the POTFIT package, and by the MCTDH subroutine rdnatpot which reads the data file.

To Compile the Program

The program can be compiled using the shell script $MCTDH_DIR/bin/compile. Type
compile potfit

to produce the executable $MCTDH_DIR/bin/$MCTDH_PLATFORM/potfit<ver>.

The compile script has various options (type compile -h for a list). For example, to produce an exectuable $MCTDH_DIR/bin/$MCTDH_PLATFORM/potfit<ver>d (e.g. potfit83d) with debug information, type

compile -d potfit

For more information on the compile script, see Compiling the Programs.

To Run the Program

The program is run from the directory containing the input file. Set up the directory to accept the data files produced, then type
path/potfitver[d][_s] [-h|-?] [-ver -rd -rv -gv -w -ig -s] [-jtot real] [-D name] inname[.inp]

where path is the pathname pointing to the executable potfitver[d][_s]. Here, ver is the version number. To choose the program version compiled with the debug flags turned on the optional letter d is appended. s represents an optional string chosen by the user at compile time. inname is the stem of the input file, which must have .inp as its file extension. One can also specify the full name inname.inp. If no input file is specified, a brief description on how to run the program is put out. The additional options include:

    -h   : print this help-text
    -?   : print this help-text
    -ver : version information
    -rd  : reading of the dvr-file is enforced
    -rv  : Reading of the vpot-file is enforced.
    -gv  : generation of the vpot-file is enforced
    -w   : overwrite enabled
    -s   : short test-run, checking the syntax of the inpf file,
           no files created, no dynamical space allocated
    -jtot: 'real' denotes a real number (jtot in ~.inp file ignored,
            but cspot option must be set)
    -D   : 'name' denotes the directory where files are written to
           (name in ~.inp file ignored)


potfit83d_new test

starts the POTFIT program version 8 release 1 compiled with the options "-d -n new" and takes the input from the file test.inp. The file test.inp must reside in the current directory or one must specify the full path, e.g.:  potfit83 ~/inputs/test

It is in general necessary to run the program on the same platform you have compiled it.

For further information on the input file see Potfit Input Documentation. There you will also find some Example Input Files.

Input Parameters

Input parameters are specified in the input file. This is detailed in the Potfit Input Documentation.

Output Data

The output data is written to a number of files. These are described in the Potfit Output Documentation.