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Alex Granovsky
gran@classic.chem.msu.su

One of the ways to restart geometry optimization run is to
search output file for the geometry having the lowest energy,
looking for strings like:

         NSERCH=  NNN     ENERGY=    EEE

Here NNN is a step number and EEE is an energy. The simplest way
to do this is to use "grep" (under Linux) or "find" (under Windows)
command line tools Note, grep is very useful and much more
powerful tool. There are many ports of grep for Windows, so you
can download and try one of them. There also exists a SUA
(Subsystem for Unix Applications) subsystems for Windows which
is available from Microsoft.

Upon locating the geometry having the lowest energy,
create a copy of your input file and replace initial
coordinates by the coordinates that correspond to the
lowest energy (these coordinates can be found in the output
a bit above the string with the lowest energy data).

Next, look at the punch file. It duplicates the most important
parts of output and contains some additional information.
For instance, it has a set formatted $vec groups that
contains MOs at all geometry optimization points. Copy
the $vec group corresponding to NSERCH with minimum energy
to the new input file and use

 $guess guess=moread norb=nnnn $end

You should replace nnnn by the actual number of MOs
(you should provide at least all populated orbitals).

That's basically all. I'll describe other ways of how to
restart optimization jobs in my next posts and also explain
how to restart hessian calculations.

Hope this helps.

Kind regards,
Alex Granovsky


On Thu May 16 '13 11:53am, Siddheshwar Chopra wrote
---------------------------------------------------
>Dear Alex,
>My jobs particularly involve geometry optimization, numerical hessian jobs, finding raman, using DFT, TDFT , mostly. Sir, I need to know the code which I have to add to my Restart i/p file, WHICH WOULD START THE CALCULATION FROM WHERE IT WAS CRASHED (OR STOPPED).. Please make me understand this well. I would be grateful if you could send me an i/p file or the commands..

>Regards,
>
>
>On Wed May 15 '13 9:55pm, Alex Granovsky wrote
>----------------------------------------------
>>Hello,
>>
>>
>>It is rather straightforward to restart geometry optimization
>>and numerical hessian jobs. Are these the types of jobs you
>>are interested in? Please let us know.

>>Several other types of jobs can be restarted as well but it is more tricky.

>>A good solution would be to buy an UPS. It would also help protecting
>>your hardware from damage due to power outages, electrical surges,  noise etc...

>>Kind regards,
>>Alex Granovsky
>>
>>
>>On Wed May 15 '13 12:04pm, Siddheshwar Chopra wrote
>>---------------------------------------------------
>>>Dear Sir,
>>>Due to erratic power cuts or other reasons, it is becoming very difficult to restart any calculations everytime.. PLEASE TELL ME is there any way I can RESTART from the same, once the FIREFLY crashes due to such power issue?? It would be a great help appreciated in advance.

>>>Regards,