[Wien] Reg. Rkmax and K point

[Stefaan Cottenier]

> For finding the suitable RKmax and K point for a transition metal or 
> compound, i am running the SCF calculation with RKmax range 7 to 10.5 
> with step of 0.5.
Your lower and higher ends are a bit high. Start at 5.5, and stop when 
you see no further evolution (rarely beyond 8.5).
>   Similarly, For k point with increment of 1000 or 2000
Also here you're taking too many steps. Roughly double the number of 
k-points at each step (doubled in the IBZ [=nr. of lines in case.klist], 
not in FBZ [=input for kgen]).
> upto 0.00001Ry of energy convergence.  Simultaneously i am looking the 
> other parameters like  CTO, Fermi energy, DIS... that the energy is 
> properly converges or not.
This criterium might be a bit strong for the sake of testing. Does 
anything meaningful changes in observable quantities if you converge 
only up to 0.000x?)

You are doing it the right way: first doing these tests before you go on 
with the more interesting work. Congratulations! Many others carelessly 
skip this part. But don't overshoot in the other direction...

Stefaan
>   But it takes very long time, before going to volume optimization or 
> mini.  If there is any other shorter method  is available, to find the 
> suitable RKmax and K point.
>  
> Thanks in advance.
>  
> Regards,
> Santhy Jaiker
>  
>
> ------------------------------------------------------------------------
> Why delete messages? Unlimited storage is just a click away. 
> <http://in.rd.yahoo.com/tagline_mail_1/*http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/> 
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>   


Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm