Hi Izaak,<div><br></div><div>You need to set lda_pu_kind = 0 to use U and J in the simplified version of DFT+U where forces are implemented.</div><div><br></div><div>Best regards,</div><div><br></div><div>Burak Himmetoglu<div>
<br></div><div><div>Post-Doctoral Associate</div><div>Materials Department</div><div>University of California at Santa Barbara</div><div>CA 93106</div></div><br><div class="gmail_quote">On Wed, Feb 27, 2013 at 8:31 AM, Izaak Williamson <span dir="ltr"><<a href="mailto:izaakw89@yahoo.com" target="_blank">izaakw89@yahoo.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div style="font-size:10pt;font-family:times new roman,new york,times,serif"><div><span style="font-size:10pt">Hello everyone,</span><br>
</div><div style="font-family:'times new roman','new york',times,serif;font-size:10pt"><div style="font-family:'times new roman','new york',times,serif;font-size:12pt"><div><div style="font-size:10pt;font-family:'times new roman','new york',times,serif">
<div style="font-family:'times new roman','new york',times,serif;font-size:10pt"><br></div><div style="font-style:normal;font-size:13px;background-color:transparent;font-family:'times new roman','new york',times,serif">
I am using the DFT+U approach to compare my system with experimental results. To do so, I want to optimize the effective on-site Coulomb value (U) and keep the exchange
value (J) fixed while simultaneously relaxing the structure using vc-relax. When I try and submit the vc-relax (or even relax) calculations, I get the following error:</div><div style="font-style:normal;font-size:13px;background-color:transparent;font-family:'times new roman','new york',times,serif">
<br></div><div style="background-color:transparent"><div style="background-color:transparent"><font face="times new roman, new york, times, serif"><span style="font-size:12.800000190734863px"> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</span></font></div>
<div style="background-color:transparent"><font face="times new roman, new york, times, serif"><span style="font-size:12.800000190734863px"> Error in routine force_hub (1):</span></font></div><div style="background-color:transparent">
<font face="times new roman, new york, times, serif"><span style="font-size:12.800000190734863px"> forces in full LDA+U scheme are not yet implemented</span></font></div><div style="background-color:transparent"><font face="times new roman, new york, times, serif"><span style="font-size:12.800000190734863px"> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</span></font><span style="font-family:'times new roman','new york',times,serif;font-size:12.800000190734863px;background-color:transparent">%%%%%%</span></div>
<div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif"><span style="font-family:'times new roman','new york',times,serif;font-size:12.800000190734863px;background-color:transparent"><br>
</span></div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif"><span style="font-family:'times new roman','new york',times,serif;font-size:12.800000190734863px;background-color:transparent">This doesn't seem right to me. Is it true what the error
says, that
the force calculations are not yet implemented in the "rotationally invariant scheme of Liechtenstein et. Al., using Hubbard_U and Hubbard_J"? Perhaps I have made a mistake in my input file. The system portion of my input file is given:</span></div>
<div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif"><span style="font-family:'times new roman','new york',times,serif;font-size:12.800000190734863px;background-color:transparent"><br>
</span></div><div style="background-color:transparent"><span style="background-color:transparent;font-size:12.800000190734863px"><font face="times new roman, new york, times, serif"><div style="background-color:transparent">
&SYSTEM</div><div style="background-color:transparent"> ibrav = 0</div><div style="background-color:transparent"> celldm(1) = 1.889725989</div><div style="background-color:transparent"> nat = 73</div>
<div style="background-color:transparent"> ntyp = 4</div><div style="background-color:transparent"> ecutwfc = 60</div><div style="background-color:transparent"> ecutrho = 600</div><div style="background-color:transparent">
occupations = 'smearing'</div><div style="background-color:transparent"> degauss = 0.001</div><div style="background-color:transparent"> nspin = 2</div><div style="background-color:transparent">
starting_magnetization(1) =
0.5</div><div style="background-color:transparent"> starting_magnetization(2) =-0.5</div><div style="background-color:transparent"> tot_magnetization= 0.0</div><div style="background-color:transparent"> lda_plus_u = .t.</div>
<div style="background-color:transparent"> lda_plus_u_kind = 1</div><div style="background-color:transparent"> Hubbard_U(1) = 2.6</div><div style="background-color:transparent"> Hubbard_U(2) = 2.6</div><div style="background-color:transparent">
Hubbard_J0(1) = 1.2</div><div style="background-color:transparent"> Hubbard_J0(2) = 1.2</div><div style="background-color:transparent">/</div><div style="background-color:transparent"><br></div><div style="background-color:transparent">
NOTE: Whenever lda_plus_u_kind is set to 1, any relax calculation
gives the above error. When it is 0, it runs fine.</div><div style="background-color:transparent"><br></div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">
Is it necessary to include "lda_plus_u_kind = 1" parameter or will the code still incorporate U and J if I set it to 0 (simplified version of Cococcioni and de Gironcoli using Hubbard_U)?</div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">
<br></div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">Thanks in advance.</div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">
<br></div><div>--</div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">Izaak Williamson</div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">
Graduate Student</div><div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">Department of Materials Science and Engineering</div>
<div style="font-style:normal;font-size:12.800000190734863px;background-color:transparent;font-family:'times new roman','new york',times,serif">Boise State University</div></font></span></div></div></div></div>
</div> </div> </div></div><br>_______________________________________________<br>
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<a href="http://pwscf.org/mailman/listinfo/pw_forum" target="_blank">http://pwscf.org/mailman/listinfo/pw_forum</a><br></blockquote></div><br><br clear="all"><div><br></div>-- <br>Burak Himmetoglu<div>Research Associate</div>
<div>Department of Materials</div><div>University of California at Santa Barbara, CA</div>
</div>