[Wien] Effect of finite nucleus on the change of electron capture decay rate under compression

[Laurence Marks]

A relevant paper may be http://yclept.ucdavis.edu/Publ/Bhf_SIC.pdf

Novak et al, PHYSICAL REVIEW B 67, 140403R, 2003.

N.B., if anyone has the code please send it to me -- I will keep a
copy (I thought I had it). Maybe it should be part of the unsupported
software.

On Tue, Jan 21, 2014 at 7:05 AM, Peter Blaha
<pblaha at theochem.tuwien.ac.at> wrote:
> I don't have this SIC code, which gave better hyperfine fields for Fe
> (but failed miserable for another test, so it might have been accidentally).
>
> Anyway, yes, try also LDA, as GGAs may behave strange at the nucleus.
>
> On 01/21/2014 01:56 PM, Laurence Marks wrote:
>> Interesting.
>>
>> Maybe relevant, maybe not. I seem to remember that conventional
>> functionals do not always do a great job near the nucleus, so there can
>> be errors in the high angle x-ray scattering factors. Some time ago
>> there was an experimental lcore which did a better job; unfortunately I
>> cannot find the reference. Peter probably has the code and, at your own
>> risk, you might want to try it.
>>
>> Beyond that you would have to change the nuclear part of the Coulomb
>> integrals in lapw0.F.
>>
>> ______________________________
>> Laurence Marks
>> Dept Mat Sci & Eng
>> Northwestern University
>> www.numis.northwestern.edu <http://www.numis.northwestern.edu>
>> 847 491 3996
>>
>> On Jan 21, 2014 4:31 AM, "Amlan Ray" <amlan_ray2005 at yahoo.com
>> <mailto:amlan_ray2005 at yahoo.com>> wrote:
>>
>>     I tried different values of R0 (R0=0.0001 BU, 0.00001 BU, 0.00004
>>     BU) for calculating the electron density at the nucleus. Of course,
>>     the electron density changes for different values of R0 and so the
>>     predicted electron capture rate also changes. However I am not
>>     trying to compare the calculated electron capture rate with the
>>     experimental result. By taking a suitable average over R0, I can
>>     probably get a good agreement between WIEN2K calculation and the
>>     experimental result. However I am interested to calculate the rate
>>     of increase of the electron density at the nucleus under
>>     compression. As I compress 7BeO lattice, the fractional change of
>>     the electron density at the nucleus (Delta_Lambda/Lambda) increases
>>     linearly with the applied external pressure. This result was
>>     obtained from both WIEN2K calculations and experiment. However the
>>     slope of the staright line (Delta_Lambda/Lambda versus Pressure
>>     plot) is very different for WIEN2K calculation and experimental
>>     result. From WIEN2K calculation, I get
>>     K_P=0.42X10^-4 (GPa)^-1, whereas expt result is K_P=(2.2+-0.1)X10^-4
>>     (GPa)^-1. The calculated value of K_P is essentially independent of
>>     R0. I tried different values of R0 and do not find any change in the
>>     calculated value of K_P. So naturally taking average over R0 will
>>     not change K_P. It is very robust. However the consideration of a
>>     finite nucleus will change the character of the wave function ( both
>>     radial and Z-dependence) within the nuclear volume. So I think the
>>     consideration of a finite nucleus will change the calculated value
>>     of K_P and it should increase the value bringing it closer to the
>>     experimental number.
>>     Isomer shift is not directly proportional to the electron density at
>>     the nucleus and people tune the calculations using experimental
>>     results. In the case of isomer shift, I am interested to know
>>     how well WIEN2K calculations agree with the change of isomer shift
>>     under compression. Please refer me to a suitable publication where
>>     the change of isomer shift under compression has been studied.
>>     With best regards
>>     Amlan Ray
>>     VECC, Kolkata
>>     India
>>
>>
>>
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>>
>
> --
>
>                                        P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
> Email: blaha at theochem.tuwien.ac.at    WWW:
> http://info.tuwien.ac.at/theochem/
> --------------------------------------------------------------------------
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html



-- 
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
www.numis.northwestern.edu 1-847-491-3996
"Research is to see what everybody else has seen, and to think what
nobody else has thought"
Albert Szent-Gyorgi