The dl_f_path file¶
When DL_FIELD is run, the dl_f_path file is the first file to read. It contains information about the directory paths of various file components. Each file precedes with a COMPONENT FILE TYPE and an equal ‘=’ sign. These are shown as follows:
LIBRARY = directory location to force field library files.
SOLVENT = directory location to solvent templates. This COMPONENT is only relevant if solvation feature is used.
OUTPUT = directory location where the output files are written out. Example output files are the converted FF model files such as dlpoly.CONFIG, dlpoly.FIELD and dlf_notation.output.
CONTROL = location and filename of the DL_FIELD control file.
CHARMM_RTF = location and filename for CHARMM’s residue topology file (rtf). DL_FIELD reads this file and converts it to the equivalent udff file to setup force field models.
CHARMM_PRM = location and filename for CHARMM’s parameter file (prm). DL_FIELD reads this file and converts it to the equivalent udff file to setup force field models.
CHARMM_PSF = location and filename of CHARMM’s protein structure file (psf). DL_FIELD reads this file and converts it to the equivalent udff file to setup force field models.
CHARMM_PDB = location and filename of a PDB file that is produced along with a matching psf file using CHARMM’s psfgen.
The remark statement is indicated with the ‘#’ symbol at the first column of the line and the rest of the information will be ignored by DL_FIELD. Below shows an example of dl_f_path file.
# Directory paths for DL_FIELD version 4.4 onwards.
# This file must be located where DL_FIELD executable is located.
# paths
library = /usr/ped2/DL_FIELD/lib/
solvent = solvent/
output = output/
control = ../control/test1.control
##########################
# optional files
# Look for CHARMM rtf, and or prm files
charmm_rtf = pentanoic_acid.rtf charmm36_cgenff
charmm_prm = pentanoic_acid.prm charmm36_cgenff
The dl_f_path must be located in the DL_FIELD home directory, which is where DL_FIELD program is run. The directory paths can be either absolute or relative (to DL_FIELD home directory) type.