[Wien] kmax for lapw3

[Peter Blaha]

The ONLY relevant quantity of lapw3 is the total X-ray structure factor. As you mentioned, it
can be calculated for any K smaller than what you specify in the input.

What you call X-rax FORM factor, is NOT the X-ray form factor known in usual X-ray crystallography.
It is a purely mathematical construct and gives the contribution to the structure factor from
an electron density within a given atomic sphere.
In particular, the total structure factor cannot be calculated from the WIEN2k atomic "from factors"
only, but there is an additional large part from the interstitial. And this contribution will
change drastically with variations of RMTs.

Thus these quantities are only listed for information and probably only up to a certain sin th/l.
Eventually you can change this directly in the source code.

Am 01.11.2011 14:38, schrieb ZhenChen:
> Dear all wien2k users,
> When I calculated the X-ray form factor of every atom in a crystal using the program lapw3, I found that the maximum sin(theta/lambda) value for X-ray FORM factor of every atom
> cannot be changed. So I'm eager to know how to get the form factors for larger sin(theta/lambda) values?
> Surely I noticed the message: "Specify max sin(theta/lambda) value (A-1)", when I executed lapw3. However, this maximum value only affects the X-Ray STRUcture factor for a unit
> cell, but not the X-ray FORM factor for every atom. I also changed the RKmax, number of k-points and gmax, but the maximum sin(theta/lambda) value calculated for the Form factors
> is never changed. So I am puzzling whether or not it can be increased manually!?
> By the way, I used both wien2k_10 and wien2k_11 versions, and tried lapw3 for several cases including the example of TiC structure. All cases seem to have common sin(theta/lambda)
> values of about 1.6A-1 ??
> All responses will be appreciated!
> Best,
> Zhen
> 2011-11-01
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> PhD. candidate Zhen Chen
> ------------------------------
> Prof. Jianqi Li's group, A06
> Beijing Laboratory of Electron Microscopy
> Institute of Physics
> Chinese Academy of Sciences
> P. O. Box 603
> Beijing 100190, China
> Tel: 86-10-82648001
> URL: http://www.blem.ac.cn/english/study-A06-1.asp
> 　　　　　　　　zchen at blem.ac.cn
>
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien

-- 

                                       P.Blaha
--------------------------------------------------------------------------
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/
--------------------------------------------------------------------------