<html>
  <head>
    <meta content="text/html; charset=windows-1252"
      http-equiv="Content-Type">
  </head>
  <body bgcolor="#FFFFFF" text="#000000">
    <tt>Hi,</tt><tt><br>
    </tt><tt><br>
    </tt><tt>You could use xcrysden to check your input.</tt><tt><br>
    </tt><tt>This is the result with your input:</tt><tt><br>
    </tt><tt>Number of Atoms:  8</tt><tt><br>
    </tt><tt>Number of Frames: 12</tt><tt><br>
    </tt><tt>WARNING: Atom 1 and atom 3 overlap !!!   Atom 3 deleted !!!</tt><tt><br>
    </tt><tt>WARNING: Atom 2 and atom 7 overlap !!!   Atom 7 deleted !!!</tt><tt><br>
    </tt><tt>WARNING: Atom 4 and atom 8 overlap !!!   Atom 8 deleted !!!</tt><tt><br>
    </tt><tt>WARNING: Atom 5 and atom 6 overlap !!!   Atom 6 deleted !!!</tt><tt><br>
    </tt><tt>That was also why pwscf showed that error.</tt><tt><br>
    </tt><tt><br>
    </tt><tt>Duc-Long</tt><tt><br>
    </tt><br>
    <div class="moz-cite-prefix">On 1/12/2016 7:46 AM, Elio Physics
      wrote:<br>
    </div>
    <blockquote
cite="mid:BLUPR10MB0754CF20A7FF996CF2D56EAFEAC90@BLUPR10MB0754.namprd10.prod.outlook.com"
      type="cite">
      <meta http-equiv="Content-Type" content="text/html;
        charset=windows-1252">
      <style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
      <div id="divtagdefaultwrapper"
style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;">
        <p>Dear Duc-Long,</p>
        <p><br>
        </p>
        <p>thanks for your response. I do not think they have the same
          coordinate. The "y" coordinate of one is
          <b>0.10168</b> while that of the 2nd is <b>1.10168, </b> that
          is a difference of 1 ang.</p>
        <p><br>
        </p>
        <p>Elio</p>
        <br>
        <br>
        <div style="color: rgb(0, 0, 0);">
          <hr tabindex="-1" style="display:inline-block; width:98%">
          <div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt"
              color="#000000" face="Calibri, sans-serif"><b>From:</b>
              <a class="moz-txt-link-abbreviated" href="mailto:pw_forum-bounces@pwscf.org">pw_forum-bounces@pwscf.org</a>
              <a class="moz-txt-link-rfc2396E" href="mailto:pw_forum-bounces@pwscf.org"><pw_forum-bounces@pwscf.org></a> on behalf of Duc-Long
              NGUYEN <a class="moz-txt-link-rfc2396E" href="mailto:longnguyenqtr@gmail.com"><longnguyenqtr@gmail.com></a><br>
              <b>Sent:</b> Monday, January 11, 2016 9:38 PM<br>
              <b>To:</b> PWSCF Forum<br>
              <b>Subject:</b> Re: [Pw_forum] Atomic positions for Black
              Phosphorus calculations</font>
            <div> </div>
          </div>
          <div><tt>Dear Elio,</tt><tt><br>
            </tt><tt><br>
            </tt>
            <div><tt>ATOMIC_POSITIONS crystal</tt></div>
            <div><tt>P  -0.89832 0.89832 0.91944</tt></div>
            <div><tt>P  -0.39832 0.39832 0.58056</tt></div>
            <div><tt><font color="#cc0000"><u>P  -0.10168 0.10168
                    0.08056</u></font></tt></div>
            <div><tt>P   0.10168 0.89832 0.91944</tt></div>
            <div><tt><font color="#cc0000"><u>P  -0.10168 1.10168
                    0.08056</u></font></tt></div>
            <div><tt>P  -0.60168 0.60168 0.41944</tt></div>
            <div><tt>P  -0.39832 1.39832 0.58056</tt></div>
            <div><tt>P   0.39832 0.60168 0.41944</tt></div>
            <tt>These two atom positions have the same coordinate. This
              could be the problem</tt><tt>.<br>
            </tt><tt><br>
            </tt><tt>Duc-Long</tt><br>
            <br>
            <div class="moz-cite-prefix">On 1/12/2016 6:44 AM, Elio
              Physics wrote:<br>
            </div>
            <blockquote type="cite">
              <div id="divtagdefaultwrapper" style="font-size:12pt;
                color:#000000; background-color:#FFFFFF;
                font-family:Calibri,Arial,Helvetica,sans-serif">
                <p>Dear all,</p>
                <p><br>
                </p>
                <p>I am trying to perform some calculations on Black
                  Phosphorus (BP).  To get the atomic positions I used
                  the Crystal Builder, where I have chosen the lattice
                  type to be base centered orthorhombic.  The "builder"
                  produced a set of cartesian and fractional  (in terms
                  of the primitive cell vectors) . I have used the
                  fractional ones and I have also used ibrav=0 with the
                  CELL_PARAMETERS defined as in the builder (a/2, -b/2,
                  0), (a/2, b/2,0), (0,0,c). However I have got the
                  following error:</p>
                <p><br>
                </p>
                <div> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</div>
                <div>     from check_atoms : error #         1</div>
                <div>     atoms #   1 and #   4 overlap!</div>
                <div> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</div>
                <div><br>
                </div>
                Doing the same calculation with ibrav=8 and using the
                coordinates produced by the Crystal builder for a simple
                orthorhombic does not produce any errors. Can anyone
                please tell me what is wrong with atoms (1) and (4). Is
                BP simple or base centered orthorhombic..Where can I
                find the coorect atomic position of bulk BP? The scf
                input is below:
                <p><br>
                </p>
                <p> </p>
                <div>&CONTROL</div>
                <div>    prefix='bp',</div>
                <div>    calculation='scf',</div>
                <div>    restart_mode='from_scratch',</div>
                <div>    wf_collect=.true.,</div>
                <div>    forc_conv_thr=1.D-4</div>
                <div>    etot_conv_thr=1.D-5</div>
                <div>    tstress=.true.,</div>
                <div>    tprnfor=.true.,</div>
                <div>    pseudo_dir
                  ='/home_cluster/fis718/elio/espresso-4.1.3/pseudo',</div>
                <div>   
                  outdir='/home_cluster/fis718/elio/espresso-4.1.3/BP/OUT'</div>
                <div> /</div>
                <div> &SYSTEM</div>
                <div>    ibrav=0,celldm(1)=6.26179,nat=8, ntyp= 1,
                  ecutwfc=10, ecutrho=40, occupations='smearing',
                  london=.true., smearing='mp', degauss=0.035,nbnd=32</div>
                <div>/</div>
                <div> &ELECTRONS</div>
                <div>    conv_thr=1.D-8,</div>
                <div>    mixing_beta=0.1</div>
                <div>/</div>
                <div>&IONS</div>
                <div>ion_dynamics='bfgs'</div>
                <div>/</div>
                <div>&CELL</div>
                <div>cell_dynamics='bfgs'</div>
                <div>press=0.0</div>
                <div>/</div>
                <div>ATOMIC_SPECIES</div>
                <div>P 30.97376  P.pbe-n-van.UPF</div>
                <div>ATOMIC_POSITIONS crystal</div>
                <div>P  -0.89832 0.89832 0.91944</div>
                <div>P  -0.39832 0.39832 0.58056</div>
                <div>P  -0.10168 0.10168 0.08056</div>
                <div>P   0.10168 0.89832 0.91944</div>
                <div>P  -0.10168 1.10168 0.08056</div>
                <div>P  -0.60168 0.60168 0.41944</div>
                <div>P  -0.39832 1.39832 0.58056</div>
                <div>P   0.39832 0.60168 0.41944</div>
                <div><br>
                </div>
                <div>K_POINTS automatic</div>
                <div> 2 2 2 0 0 0</div>
                <div><br>
                </div>
                <div>CELL_PARAMETERS alat</div>
                <div>0.5000 -1.58106 0.0000</div>
                <div>0.500 1.58106 0.0000</div>
                <div>0.0000 0.00000 4.3763</div>
                <div><br>
                </div>
                <div><br>
                </div>
                <div>thanks</div>
                <div><br>
                </div>
                <div>Elio Arbid</div>
                <div>University of Nottingham</div>
                <div>UK</div>
              </div>
              <br>
              <fieldset class="mimeAttachmentHeader"></fieldset>
              <br>
              <pre>_______________________________________________
Pw_forum mailing list
<a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://pwscf.org/mailman/listinfo/pw_forum">http://pwscf.org/mailman/listinfo/pw_forum</a></pre>
            </blockquote>
            <br>
            <pre class="moz-signature" cols="72">-- 
Duc-Long Nguyen
Graduate Student, Molecular Science and Technology Program, TIGP
Institute of Atomic and Molecular Sciences,
Academia Sinica, Taipei 106, Taiwan
Phone +886 979279073</pre>
          </div>
        </div>
      </div>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <pre wrap="">_______________________________________________
Pw_forum mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a>
<a class="moz-txt-link-freetext" href="http://pwscf.org/mailman/listinfo/pw_forum">http://pwscf.org/mailman/listinfo/pw_forum</a></pre>
    </blockquote>
    <br>
  </body>
</html>