(This program is not a function within MOPAC, instead it is a utility program for building data sets for polymers, layer systems, and solids. MAKPOL was extensively rewritten in January, 2018. A copy of the MAKPOL executable for use on WINDOWS systems is available for download.)
MAKPOL can convert a file in PDB or ENT format into a MOPAC data-set. These files have exactly the same format, so in principle either suffix could be used. However, since MOPAC can generate files that have the PDB suffix, it's better to use files with the suffix .ENT with MAKPOL; there is less chance that ENT files would be accidentally over-written. ENT files can either be created by the user or generated from a CIF file. Two good sources are the Cambridge Structural Database, the CSD, for organic solids, and the Inorganic Crystal Structure Database, the ICSD, for inorganic solids.
Download the MAKPOL executable and extract the files in the ZIP file to a convenient place, for example to Users/yourname/MAKPOL. Then place a shortcut on the desktop. To do this, copy the MOPAC executable and paste a shortcut on the desktop. Then drag-and drop any of the examples in the ZIP file onto the shortcut. The job will run very fast - must less than one second.
Files in PDB format normally include data on the unit cell. These data can be seen in the line that starts with the letters "CRYST1"
To prevent accidental over-writing of the input file, if the file's suffix is PDB re-name the suffix to ENT. Then "drag-and-drop" the ENT file onto the MAKPOL shortcut icon. The job should run in about a second, and produce two files. These will be named <file>.mop and Make_<file>.dat. <file>.mop is an ordinary MOPAC data-set. If any changes need to be made to the cluster in <file>.mop, the easiest way to make these changes is to edit Make_<file>.dat and then run Make_<file>.dat using MAKPOL. That will over-write <file>.mop.
Any file in MOPAC format (keywords - title - comment - geometry) that has enough information to allow the translation vectors to be generated can be used with MAKPOL. Suitable names for data-sets in MOPAC format are <file>.dat and Make_<file>.dat, although almost any other name could be used. Avoid a name that is the same as the file-name created by MAKPOL, i.e., avoid <file>.mop.
When MAKPOL is run, it will create a file Make_<file>.dat, if that file does not already exist. This file is in MOPAC format, and can be edited as necessary, and then used as a data-set for MAKPOL. That allows changes to be made easier than if the changes had to be made to the original data-set.
Any of the keywords used by MOPAC can be used in a MAKPOL data set, but, only a few keywords will be used by MAKPOL; the rest will be ignored. Keywords that are used in MAKPOL are given below.BCC
It is often convenient to have a set of keywords in the <file>.mop file generated by MAKPOL, that are intended for use in a MOPAC job. To allow this, a second data-set file, named "keywords for MAKPOL.txt" can be used by MAKPOL. This file should contain all the keywords that the resulting MOPAC data-set should contain. This file can be empty or it can hold commonly-used MOPAC keywords, such as "0SCF HTML"