<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><DIV><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><BR class="Apple-interchange-newline"></SPAN> </DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Dear Paul,</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>I have no experience with CuO and can't give you a very useful advise. I suspect that even if you change occ_loc = 9 for Cu the </DIV><DIV>code will converge to the same ground state. This is however quick to try and you may find better results (sometimes the code gets trapped in </DIV><DIV>local minima with a finite U).</DIV><BR><DIV><DIV>On Dec 13, 2007, at 6:26 AM, Henning Glawe wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">On Wed, Dec 12, 2007 at 11:40:56PM -0800, Paul M. Grant wrote:</DIV> <BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Simplistically, the initial d-state configuration of Cu2+ in CuO by Hund’s</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Rule should be 3d9 (one empty minority spin state state…a hole). <SPAN class="Apple-converted-space"> </SPAN>But, with</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">nspin=2, lda_plus_u set true, and U=5 eV (arbitrary), the initial minority</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">spin occupation gets set to unity, not 4/5 on average (3/5 for Ni and 1/5</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">for Fe).<SPAN class="Apple-converted-space"> </SPAN>Is this due to occ_loc being set to 10 in tabd.f90 and not 9 (it’s</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">6 for Fe and 8 for Ni)?<SPAN class="Apple-converted-space"> </SPAN>The occupation distribution converges to around</DIV> </BLOCKQUOTE><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">as the d shell can be filled with 10 electrons, getting a initial hole into the<SPAN class="Apple-converted-space"> </SPAN></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">d shell while occ_loc=10 is IMHO impossible.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV> <BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">functionals have equivalent occupations and give similar results).<SPAN class="Apple-converted-space"> </SPAN>When I</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">try Cu.pz-d-rrkjus.UPF, with 3d10, 4s1 and 4p-1(!!!), the first scf</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">iteration yields individual spin occupations of nearly 5(!!!), and the</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">situation gets really ugly thereafter.</DIV> </BLOCKQUOTE><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">I also encountered this problem with this pseudo potential; the problem lies</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">in the normalization of the 3d wave functions saved in the pp file. if you</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">search in the archives of the pw forum, you will find a patch for pwscf</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">allowing to recalculate the norm of the atomic states after the pp file has</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">been read.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>the patch has been implemented in the cvs version of the code. if you download it and read INPUT_PW</DIV><DIV>you find the following lines (you are interested in norm-atomic):</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>U_projection_type CHARACTER (default='atomic')</DIV><DIV> Only active when lda_plus_U is .true., specifies the type</DIV><DIV> of projector on localized orbital to be used in the LDA+U</DIV><DIV> scheme.</DIV><DIV> Currently available choices:</DIV><DIV> 'atomic': use atomic wfc's (as they are) to build the projector</DIV><DIV> 'ortho-atomic': use Lowdin orthogonalized atomic wfc's</DIV><DIV> 'norm-atomic': Lowdin normalization of atomic wfc. Keep in mind:</DIV><DIV> atomic wfc are not orthogonalized in this case.</DIV><DIV> This is a "quick and dirty" trick to be used when</DIV><DIV> atomic wfc from the pseudopotential are not</DIV><DIV> normalized (and thus produce occupation whose</DIV><DIV> value exceeds unity). If orthogonalized wfc are</DIV><DIV> not needed always try 'atomic' first.</DIV><DIV> 'file': use the information from file "prefix".atwfc that must</DIV><DIV> have been generated previously, for instance by pmw.x</DIV><DIV> (see PP/poormanwannier.f90 for details)</DIV><DIV> NB: forces and stress currently implemented only for the</DIV><DIV> 'atomic' choice.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Hope this helps.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Matteo</DIV><DIV><BR class="khtml-block-placeholder"></DIV><BR><BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">--<SPAN class="Apple-converted-space"> </SPAN></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">c u</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">henning</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">_______________________________________________</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Pw_forum mailing list</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><A href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</A></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><A href="http://www.democritos.it/mailman/listinfo/pw_forum">http://www.democritos.it/mailman/listinfo/pw_forum</A></DIV> </BLOCKQUOTE></DIV><BR></BODY></HTML>