potfit wiki

Converts force files produced by [http://imd.itap.physik.uni-stuttgart.de/ IMD] and used by potfit to [http://cms.mpi.univie.ac.at/vasp/ VASP] input file POSCAR.

Compilation: <tt>make force2poscar [-DSTRESS]</tt>

Usage: force2poscar input.force

The information is always written to a file called POSCAR residing in the local directory. Use compile option -DSTRESS if your force file includes stress tensor information.

Converts [http://cms.mpi.univie.ac.at/vasp/ VASP] output to force files.

Compilation: <tt>make vasp2force</tt>

Usage: vasp2force [-c list] [-e file] [-f] [-l] [-r] [-s list] <OUTCAR files>

Reads information from all OUTCAR files in the current directory. <OUTCAR files> is an optional list of files, if not given all files matching OUTCAR* will be scanned (it is possible to read gzipped files ending with .gz). An optional file can be specified, containing the energy of a single free atom calculated by [http://cms.mpi.univie.ac.at/vasp/ VASP] in a single line in the same order as in the OUTCAR file, e.g.:

# Al Co Ni -0.000219 -0.993872 -0.855835

Writes a force file to be used as a potfit reference configuration to standard output. If no options are given, force data is generated from each ionic step.

Options:

<tt>-c <list></tt> :list of chemical species to use (e.g. “vasp2force -c Al=0,Mn=1,Pd=2”). This will force all atom types in all configurations to be consistent. <tt>-e <file></tt> :Specify file to read single atom energies from; if not found, “0” will be used for every atom type. <tt>-f</tt> :Uses only final configuration of multiple ionic steps. <tt>-l</tt> :List all chemical species found in OUTCAR and exit. <tt>-r</tt> :Scan recursively for OUTCAR files in every subdirectory. <tt>-s list</tt> :List is a comma separated list of ionic steps to use, e.g. “1,4,7,9”. The sequence of the force data is always the same as in the OUTCAR file, independent of the sequence given in the list. Every configuration mentioned appears exactly once. <tt>-w weight</tt> :Assign this weight to all configurations.

Converts betweeen various potential models.

Compilation: <tt>make pottrans</tt>

Usage: pottrans <paramfile>

required parameters in paramfile (here with example values)

<pre>
ntypes     2           # number of atom types
ncols      3           # number of output potentials
infile     in.pot      # input potential file for pair potentials
outfile    out.pot     # output potential file
nsteps     20 20 20    # number of steps for the output potentials
atomic_e-density_file  rho.pot   # atomic density for EAM potentials
embedding_energy_file  embed.pot # embedding energy for EAM potentials
core_potential_file    phi.pot   # pair potential for EAM potentials

#optional parameters

reorder     0 1        # permutes order of potentials in final file,
                       # ntypes parameters necessary
r_start   1.8 1.8 1.8  # minimal r for each column in output potential
</pre>

in.pot is converted to out.pot. in.pot can be of IMD potential format 1 or 2, out.pot is of potfit potential format. For EAM potentials, specify the appropriate number of columns in ncols and the required IMD format potential files. The order of the different atom types can be changed with the reorder parameter by specifying the desired sequence.

To convert from potfit to IMD use potfit with opt 0 in parameter file.

Lists all configurations in a config file.

Compilation: <tt>make list_config</tt>

Usage: list_config <config_file>

Scans a potfit configuration file and lists all configurations found. This includes the origin (if comment is found), the starting line, number of atoms and weight of the configuration.

This utility generates a simple parameter file for potfit.

Usage: potfit_setup [-c config file] [-p potential file] [-s prefix]

<tt>-c <config file></tt> :name of the configuration file <tt>-p <potential file></tt> :name of the potential file (for analytic potentials this can easily be created with the <tt>makeapot</tt> script from the awkscripts) <tt>-s <prefix></tt> :prefix for all files, overrides -c and -p :the following files will be checked: <tt><prefix>.pot</tt> and <tt><prefix>.config</tt> if they are not found, -c and -p will be read

The awk scripts are listed on a separate page.

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potscale performs gauge transformations on EAM potentials.

Compilation: <tt>make potscale</tt>

Usage: potscale <paramfile>

Required parameters in paramfile:

<pre>
ntypes		# number of atom types (types vary in [0..ntypes-1]) 
startpot	# file name for starting potential (*)
endpot		# file name for final potential (*)
imdpot		# file name prefix for imd potential (*)
plotfile	# file name for plotting potential (*)
plotpointfile	# file name for plotting the sampling points (*)

imdpotsteps 	# number of points in each function in imd file
dummy_r		# Distance, where dummy_rho and dummy_phi are used (ignored)

#optional options
dummy_rho 	# dummy value of rho at dummy_r
dummy_phi	# vector (length ntypes) dummy values of phi_ii at dummy_r
</pre>

Prints the values of <math>\rho_0\,</math>(dummy_r) and <math>\Phi_{ii}\,</math>(dummy_r).

If dummy_phi is given, the potential is transformed so that <math>\rho_0</math>(dummy_r)=dummy_rho and <math>\Phi_{ii}</math>(dummy_r)=dummy_phi_ii.

IMD potentials and potential plot files are also written.