Windows - set permissions
MOPAC2016 needs to be able to read and write files in the folder
that holds the file MOPAC2016.exe. Normally, this folder is "C:\Program
Files\MOPAC" In Windows this folder is write-protected by default,
so MOPAC2016 will not be able to write the password file. Before MOPAC2016 can
write its own password file, the permissions on the folder must be changed. To
do this, use the following instructions:
How to set permissions on the MOPAC folder
Using Windows Explorer (Windows-7) or File Explorer (Windows-10), navigate to "C:\Program Files"
Right-click on the folder "MOPAC" then left-click on "Properties" (this is
at the bottom of the pop-up window)
In the box "MOPAC Properties," click on "Security," then click on the button
marked "Edit" - this allows you to change permissions.
In the new window, "Permissions for MOPAC," go to "Group or user names" and
- In the "Permissions for Users" box, put a tick in the "Allow" box for
"Full control" This will automatically put ticks in the "Modify" and "Write"
- Click on "OK" to close the "Permissions for MOPAC" window.
- In the "MOPAC Properties" window, click on "Users" in the box "Group or
user names" - now the "Permissions for Users" should have ticks under the
- Click on "OK" at the bottom of the "MOPAC Properties" window.
If MOPAC2016.exe is put in a different folder, then the Environmental
Variable must be set, and the folder must have permission for "Users" to write
to the folder.