<p dir="ltr">Interesting. </p>
<p dir="ltr">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.</p>
<p dir="ltr">Beyond that you would have to change the nuclear part of the Coulomb integrals in lapw0.F.</p>
<p dir="ltr">______________________________<br>
Laurence Marks<br>
Dept Mat Sci & Eng<br>
Northwestern University<br>
<a href="http://www.numis.northwestern.edu">www.numis.northwestern.edu</a><br>
847 491 3996</p>
<div class="gmail_quote">On Jan 21, 2014 4:31 AM, "Amlan Ray" <<a href="mailto:amlan_ray2005@yahoo.com">amlan_ray2005@yahoo.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<div style="font-size:12pt;font-family:times new roman,new york,times,serif">
<div>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, t<var></var>he 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 </div>
<div>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.
</div>
<div> </div>
<div>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.
</div>
<div> </div>
<div>With best regards</div>
<div>Amlan Ray</div>
<div>VECC, Kolkata</div>
<div>India</div>
</div>
</div>
</blockquote></div>