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<p>Hi Pascal,</p>
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</p>
<p> When I first started using QE 6.0 not long ago I had trouble using crystal_sg, I suppose you have the Wyckoff positions of your atoms. What I did was use the VESTA program which allows you to input Wyckoff positions and it will correctly generate the
cell as long as other options are correct. I then exported to an xyz file and converted the coordinates in angstroms to internal crystal coordinates ('crystal' option) using:</p>
<p><a previewremoved="true" id="LPlnk549300" href="https://en.wikipedia.org/wiki/Fractional_coordinates" class="OWAAutoLink">https://en.wikipedia.org/wiki/Fractional_coordinates</a></p>
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<a target="_blank" href="https://en.wikipedia.org/wiki/Fractional_coordinates" style="text-decoration: none;" id="LPUrlAnchor_14878764206990.6963013171659084">Fractional coordinates - Wikipedia</a></div>
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en.wikipedia.org</div>
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In crystallography, a fractional coordinate system is a coordinate system in which the edges of the unit cell are used as the basic vectors to describe the positions ...</div>
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<p>Which worked perfectly for me. This is easily done with a Python script or something similar!</p>
<p><br>
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<p>Kindest regards,</p>
<p>Louis<br>
</p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> pw_forum-bounces@pwscf.org <pw_forum-bounces@pwscf.org> on behalf of Pascal Boulet <pascal.boulet@univ-amu.fr><br>
<b>Sent:</b> 23 February 2017 07:56:16<br>
<b>To:</b> PWSCF Forum<br>
<b>Subject:</b> [Pw_forum] Symmetry recognition</font>
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<div>Dear all,
<div><br>
</div>
<div>I am running a structural optimization with QE 6.0. The structure is orthorhombic, ibrav=8, with 8 symmetry elements. The first run did not converge so I have to restart it. But as I restart it, the number of symmetry is now 4, there is a descent of symmetry.
I shall say that I use the space_group option with COORDINATES crystal_sg. But the problem remains if I put all the coordinates (unsurprisingly).</div>
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<div>Is there a reason for this, and can I avoid this?</div>
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<div>Thank you</div>
<div>Best regards</div>
<div>Pascal</div>
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<div>-<br>
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<span style="color: rgb(34, 187, 234); font-size: 14px; font-family: verdana; font-weight: 700;">Pascal Boulet</span> <span style="color: rgb(34, 187, 234); font-size: 11px; font-family: verdana;"><em>- MCF HDR, Resp. L2 MPCI - DEPARTEMENT CHIMIE</em></span></div>
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