Firefly and PC GAMESS-related discussion club


 
Learn how to ask questions correctly  
 
 
We are NATO-free zone
 


Re^4: How to speed up the HESSIAN calculations

Siddheshwar Chopra
sidhusai@gmail.com

Dear Thomas,
Thank you for a prompt reply. I am glad to know that I have already specified most of the important keywords. Regarding your suggestion of FDIFF=.t., I am unsure about it, as I am unsure that even after OPTTOL=10E-7, the geometry has converged or not... At 10E-7, it did converge though... But unsure whether it is the global minimum or not...For that I am running Hessian calculations now.

Regards,

On Tue Jan 8 '13 5:01pm, Thomas wrote
-------------------------------------
>Dear Siddheshwar,

>To me, it seems you are already specifying most keywords important for performance. The only thing I can recommend is to change the value of FDIFF to .T., provided you're not having any problems with the SCF being close to converging but not quite reaching it.

>The only other way I see to speed up your calculations is to reduce accuracy (which you probably don't want for a seminumerical calculation). Perhaps someone else has some more tips for you.
>
>
>Kind regards,
>Thom
>
>
>
>
>On Tue Jan 8 '13 3:01pm, Siddheshwar Chopra wrote
>-------------------------------------------------
>>Dear Thomas,
>>As asked by you, I am hereby attaching the SAMPLE.inp for your reference. Please suggest me what to do? This sample is the smallest of all.

>>Regards,

>>On Tue Jan 8 '13 11:51am, Thomas wrote
>>--------------------------------------
>>>Dear Siddheshwar,

>>>Could you be a bit more specific? For example, could you post the input file you've been using so far for Hessian calculations? Otherwise, your question is too general for us to be helpful. :-)
>>>
>>>
>>>Kind regards,
>>>Thom
>>>
>>>
>>>
>>>
>>>On Tue Jan 8 '13 7:29am, Siddheshwar Chopra wrote
>>>-------------------------------------------------
>>>>Dear Sir,
>>>>I wish to know if there are any ways I could SPEED up the HESSIAN calculations?

>>>>Regards,

[ Previous ] [ Next ] [ Index ]           Wed Jan 9 '13 11:51am
[ Reply ] [ Edit ] [ Delete ]           This message read 895 times