-add-shells <species>
This option creates shells (in the sense of an ionic core-shell model) for a given atomic species. If <species> is "all" then shells are created for all atoms; otherwise they are created only for the specified atom species.
If some atoms already have shells and <species> is set to "all", then the shells are first deleted, and then created for all atoms.
Note that the shells positions can be output only to some specific formats, like the GIN format or the DL_POLY 4 format. When writing to other formats, the shells are not written and will be lost.
By default no shell is introduced.
atomsk system.cfg -add-shells O system.gin
This will read the file initial.gin, add shells on all oxygen ions, and write the result to the GULP file system.gin.
atomsk initial.cfg -add-shells all final.gin
This will create shells for all atoms.
atomsk initial.cfg -add-shells Ti -add-shells O final.gin
This will create shells for Ti and O atoms.