Multiple structures

Several structures can be run in one job.  To do this, construct MOPAC data-sets for each structure, then join all the data-sets together to make a new MOPAC data-set that contains all of the structures.  Each structure (individual MOPAC data-set) should be separated from the next structure by a blank line.

Warnings:

* If any of the individual MOPAC data-sets uses EXTERNAL to change the values of parameters for a method, all subsequent structures that use that method will also be affected.

* Avoid using keyword GEO_DAT.  When GEO_DAT is present, the input file has to be re-read.  This causes problems when the job has more than one structure.

Example of a data-set that has several structures.