[Wien] cnorm for Laplacian calculation

[Peter Blaha]

I don't know how exactly you got the laplacian, but my first guess
concerning the factor 2 would be that you did not consider the spin.

In lapw0 everything is done spin-polarized, even in a non-spinpolarized
calculation and one has to add spin-up and dn laplacians to get the
total.

I guess the rest is ok. The normalization of clmsum and clmval files are
different (only inside the spheres!), this explains the factor sqrt(4pi),
but the r2v file has the "clmval" normalization.


Dr. Georg Eickerling schrieb:
> Dear WIEN users,
> 
> I have a question concerning the use of LAPW5 to calculate the Laplacian 
> of the Density on a grid.
> 
> Using lapw0  [WIEN2k_08.1 (Release 14/12/2007)] I can obtain an r2v file 
> containing the information
> about the Laplacian and copying the r2v to clmval I can use lapw5 to 
> obtain grid files.
> 
> I specify atomic units in the lapw5 input to keep WIEN from applying 
> some conversion factors from
> e bohr-3 to e A-3 which would be useless in  this case and in addition I 
> specify the keyword VAL.
> 
> This works all well and the plots in XCrysden look resonable but 
> comparing the absolute values from WIEN
> to those obtained by experiment WIEN gives results which are too small 
> by something close to a factor of 2
>   (which seems not to be "real" as the topological parameters obtained 
> by WIEN's aim at the bond critical
> points are VERY close to the experimental values).
> 
> In lapw5 I can specify "TOT" of "VAL" for the "normalization" which 
> results in a division by a factor Sqrt(4Pi) in the
> case of using "TOT". My first (general) question is: What is the reason 
> for this additional factor for the total density?
> 
> Any then the second question: What would be the "proper" way to obtain 
> the Laplacian in atomic units with LAPW5,
> should I use VAL or TOT or is there some other normalization/unit 
> conversion I would have to do?
> 
> Thanks in advance for any help!
> 
> Georg Eickerling
> 
> 
> 
> 

-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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