Firefly and PC GAMESS-related discussion club


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



Re^2: Need help regarding using Symmetry and multiplicity both..

Siddheshwar Chopra
sidhusai@gmail.com


Dear Alex,
What could be the possible errors you are pointing to? Please find attached an i/p file.

Regards,

On Thu Feb 20 '14 1:21am, Alex Granovsky wrote
----------------------------------------------
>Dear Siddheshwar,

>>1) I understand when RHF is used and when ROHF.. Now could anyone clarify:
>>TO MAKE EVEN NO. OF ELECTRONS (assuming the system has odd no. of electrons) IN SYSTEM, I CAN EITHER ADD +1 OR -1 CHARGE USING icharg... �(FOR RHF)
>>SECOND WAY I CAN ALSO CHANGE THE MULTIPLICITY OF THE SYSTEM AND RUN ROHF... BUT BY DOING THIS I HAVE ADDED A SPIN TO THE SYSTEM..
>>Please tell me... Are not both ways same?? Don't both the ways mean that I have added an electron?
>
>
>1) Normally, there should be some physical or chemical ground (a model)
>behind your QC computations. This model defines what should the
>appropriate multiplicity and the overall charge be.

>>2) I was running RHF on of such cluster with C1 symmetry and even no. of electrons. It worked well. But when I added symmetry to the i/p file and added ONLY the symmetry atoms, then I got errors: a) ODD no. of electrons. Cant run RHF �and b) too many primitive bend coordinates. For around 70 atoms in total (with C1)
>>How should I go about this problem now? I want to use symmetry in my case.

>2) This means you have made some errors in your input file.

>Kind regards,
>Alex Granovsky

>On Mon Feb 10 '14 2:53pm, Siddheshwar Chopra wrote
>--------------------------------------------------
>>Dear Sir,
>>I am stuck with some doubts and not able to get them clarified at all. They are::

>>Say I have a CxHyMetal cluster...
>
>
>>Please help.
>>
>>
>>

This message contains the 3 kb attachment
[ SAMPLE_1.inp ]


[ Previous ] [ Next ] [ Index ]           Tue Feb 25 '14 12:25pm
[ Reply ] [ Edit ] [ Delete ]           This message read 425 times