Ceilidh ... Re^9: Error: Failure to locate stationary point. Too many steps taken..

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Re^9: Error: Failure to locate stationary point. Too many steps taken..

Dear Pavel,
I am providing you the input Sir. Please help me understand this DIFFICULT process of optimizing the sample. I have been trying for many days to optimize this. Please help sir. I don't want to continue like a lost person. I want to understand what I am doing properly. Please suggest me what to do.
In addition I would say that when I kept OPTTOL=1E-5, I got the convergence. But when running for Hessian, I get the error as seen from the output file. How do I speed up the optimization? Here in India the power supply is discontinuous, so it is getting very tough for me to even learn to run programs for larger molecules.

Regards,

On Sat Dec 29 '12 1:04am, Solntsev Pasha wrote
----------------------------------------------
>Dear Siddheshwar
>Could you provide input file? It is useful to check for hidden mistakes.

>Pavel.
>
>
>
>On Fri Dec 28 '12 10:03pm, Siddheshwar Chopra wrote
>---------------------------------------------------
>>Dear sir,
>>I just ran exetyp=check, before running hessian calcs. And i got the message.....scf did not converge....perform more gradient runs.... so is this sufficient to conclude that global minimum is still far??? I mean do i save myself from running hessian calcs. to confirm it?

>>n Fri Dec 28 '12 1:44am, Alex Granovsky wrote
>>----------------------------------------------
>>>Dear Siddheshwar,

>>>strictly speaking, this statement means that a stationary point was
>>>located (i.e. the point where gradient is zero). This statement does
>>>not mean that the stationary point which was located is a minimum.
>>>To check this, you need to perform Hessian computations as suggested
>>>by Luca.

>>>Kind regards,
>>>Alex Granovsky
>>>
>>>
>>>On Thu Dec 27 '12 8:49pm, Luca Maidich wrote
>>>--------------------------------------------
>>>>Dear Siddheshwar,
>>>>the only way I know for being sure that you correctly found a stationary point is to run a frequency analysis job. It is a tedious job but it has to be done.
>>>>Two considerations:
>>>>a) if you loose too much OPTTOL value your optimization could lead to non-meaningful results;
>>>>b) are you sure that what you are doing now is NOT more tedious than running optimization+frequency jobs? :)

>>>>Kind Regards
>>>>Luca

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