Firefly and PC GAMESS-related discussion club

 
Learn how to ask questions correctly  
 
 

 

Alex Granovsky
gran@classic.chem.msu.su

I agree with Luca DLC scans are much simpler.

As to your original input, you probably need to set orig1 to zero
as it is the displacement relative to current geometry. This allows
calculations to proceed. Unfortunately, they still bombs out at later stage.
The reason is huge distortion of geometry during scan and the absence
of analogs of "reuse" option and some more advanced logic programmed
for scans in DLCs. More precisely, starting points in 2D scan do not
utilize geometry info available from the previous calculations,
and thus apply geometry change directly to the initial structure.
Fore ill-defined internals, this can cause significant side-effects
like geometry distortions. The possibility of changing this behavior
has already been discussed on the forum some time ago and the
corresponding option will be available in the Firefly 8.0.0.

Best regards,
Alex Granovsky

On Sat Nov 5 '11 2:16am, Luca Maidich wrote
-------------------------------------------
>Dear Peter,
>unfortunately I've not been able to open your input file even copying and pasting it in a new file so I didn't see your molecule. Anyway, unless you have specific reason to use zmat coordinate, you could try the delocalized coordinates (DLCs) automatically generated by Firefly.
>Their usage is very simple and defining the coordinates to operate the 2D rsurface task is much easier. If you can attach the input file (not just putting it into the text message) I'll can have a better look at your problem and suggest you a possible solution with DLCs.

>However if you wish to try on your own you can search in the manual and have a look at this post http://classic.chem.msu.su/cgi-bin/ceilidh.exe/gran/gamess/forum/?C34df668afbHW-7292-202+00.htm where there is an almost complete list of all the parameters to control the generation of the delocalized coordinates.

>If you search in the forum for PES scans you should also find more examples on how to use runtyp=rsurface together with DLCs.

>Hope this helps,
>Best Regards
>Luca Maidich