[Wien] FW: FW: [Wien2k Users] ENE Warning

Stefaan Cottenier Stefaan.Cottenier at UGent.be
Fri Dec 18 09:17:12 CET 2009


> I do have f-states in my case. 
> I want to know if it is advisable to take these f-states in the valence and
> do the calculation. 
> Would it be more accurate? 
> Moreover, during lstart, we give -6.0 Ry as the separation energy between
> core and valence. 
> 
> If we put -4.5 Ry, then does it mean that we include f-states in the valence
> as well or when we put -8.0 Ry?

No-one can answer this without seeing your case.outputst, or at least 
knowing which element with f-electrons you consider.

> I am not studying the system under high pressure. 
> I guess you have come to this conclusion by seeing RKmax (Please mention if
> I am wrong) 
> Rkmax is 9.50 in my case. 

No, because you had f linearization energies of 1.6 Ry. This might 
indicate a very high fermi energy, which could be due to either a wrong 
case.struct or to high pressure.

> Actually, I would like to be more accurate in the total energy till the
> second decimal place. So I kept on changing the RKmax until it gave the same
> total energy till the second decimal place. 

Not useful, as the accuracy in the total energy itself is not needed for 
almost all properties. What you need is accuracy in total energy 
*differences*. Repeat your calculations for a slightly different lattice 
constant, and observe at which rkmax the energy difference between both 
cases converges to the precision you want. This will happen at a much 
smaller rkmax than your present one.

Stefaan



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