<div>Dear <font size="2">Stefano de Gironcoli</font><br><br>Thanks a lot for your instructive and informative comments.<br><br>-- <br>Sincerely Yours<br>David G.<br>JCU<br> </div><blockquote style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;" class="gmail_quote">
<font size="2">In a pseudopotential calculation core electrons are not there so if you <br></font><font size="2">want to "see" the core electrons you need to do an all-electron <br></font><font size="2">calculation or a PAW calculation where the total charge is reconstructed.<br>
</font><font size="2">If you are interested in knowing a total atomic charge this is easy... <br></font><font size="2">just add to the valence electron charge the number of (completely <br></font><font size="2">filled) core electrons, change sign and add the nuclear charge..<br>
</font><font size="2">notice however that the decomposition of a charge distribution in <br></font><font size="2">atomic contribution is a somewhat ill defined procedure and Lowdin <br></font><font size="2">procedure is just one possibility, so do not attach too much <br>
</font><font size="2">significance to minor changes from system to system...<br><br></font><font size="2">Something that can be useful to identify bonding in your system can be <br></font><font size="2">the analysis of the projected density of states on atomic levels of <br>
</font><font size="2">nearest-neighbor atoms. It is sometime possible to see peaks occurring <br></font><font size="2">in the same energy range for the two atoms that signal that electronic <br></font><font size="2">states in that energy range are shared between the two atoms as one <br>
</font><font size="2">expect in a covalent bond.<br><br></font><font size="2">Hope it helps.<br><br></font><font size="2">Stefano de Gironcoli</font><br></blockquote><pre><font size="4"><br><font size="4">David Grifith wrote:<br>
><i> Dear Heather<br></i>><i><br></i>><i> Thanks for your comments. I think that this type of charge (Lowdin) which is<br></i>><i> nearly the number of valence electrons can not speak about the details of<br></i>><i> the system.<br>
</i>><i> Some electrons are bonding and also, the effect of the core (core electron +<br></i>><i> nucleus ) is not negligible. I want to compare the real charge of two atoms<br></i>><i> in my system with each other not their valence electrons. I appreciate your<br>
</i>></font></font><i><font size="4"> help in advance.</font><br></i></pre><br clear="all"><br><br><br>