<div dir="ltr"><div><div><div><div><div>Hello,<br><br></div>I'm confusing, I need to do some convergence test, but I don't know if I need primitive or one unit cell and how to select it.<br><br></div>I'm using this structure <a href="http://www.crystallography.net/cod/1513984.html">http://www.crystallography.net/cod/1513984.html</a><br><br></div>I extracted the crystallographic translation. The cell formula units are 8, has 56 atoms. See ATOMIC_POSITIONS bellow.<br><br>One unit cell of LiMn2O4 (spinel) has 7 atoms.<br></div><b><br></b></div>I have the following questions:<b><br></b><div><div><br><b><b>Do I need to put 7 atoms in the primitive cell or how many?<br><br></b>How can I select the atoms position for primitive or one unit cell?</b><br><br>ATOMIC_POSITIONS alat <br>  Li     0.125000000   0.125000000   0.125000000   <br>  Li    -0.125000000   0.875000000   0.875000000   <br>  Li     0.875000000  -0.125000000   0.875000000   <br>  Li     0.875000000   0.875000000  -0.125000000   <br>  Li    -0.125000000  -0.125000000  -0.125000000   <br>  Li    -0.125000000   0.375000000   0.375000000   <br>  Li     0.375000000   0.875000000   0.375000000   <br>  Li     0.875000000   0.375000000   0.375000000   <br>  Mn     0.500000000   0.500000000   0.500000000   <br>  Mn    -0.500000000   1.250000000   1.250000000   <br>  Mn     1.250000000  -0.500000000   1.250000000   <br>  Mn     1.250000000   1.250000000  -0.500000000   <br>  Mn    -0.500000000  -0.500000000  -0.500000000   <br>  Mn     0.500000000  -0.250000000  -0.250000000   <br>  Mn    -0.250000000   0.500000000  -0.250000000   <br>  Mn    -0.250000000  -0.250000000   0.500000000   <br>  Mn    -0.500000000   0.750000000   0.750000000   <br>  Mn     0.000000000   1.250000000   0.750000000   <br>  Mn     0.000000000   0.750000000   1.250000000   <br>  Mn     1.250000000   0.000000000   0.750000000   <br>  Mn     0.750000000  -0.500000000   0.750000000   <br>  Mn     0.750000000   0.000000000   1.250000000   <br>  Mn     1.250000000   0.750000000   0.000000000   <br>  Mn     0.750000000   1.250000000   0.000000000   <br>   O    -0.262700000   1.012700000   1.012700000   <br>   O     1.012700000  -0.262700000   1.012700000   <br>   O     1.012700000   1.012700000  -0.262700000   <br>   O    -0.262700000  -0.262700000  -0.262700000   <br>   O     0.262700000  -0.012700000  -0.012700000   <br>   O    -0.012700000   0.262700000  -0.012700000   <br>   O    -0.012700000  -0.012700000   0.262700000   <br>   O     0.262700000   0.262700000   0.262700000   <br>   O    -0.262700000   0.512700000   0.512700000   <br>   O     0.237300000   1.012700000   0.512700000   <br>   O     0.237300000   0.512700000   1.012700000   <br>   O     1.012700000   0.237300000   0.512700000   <br>   O     0.512700000  -0.262700000   0.512700000   <br>   O     0.512700000   0.237300000   1.012700000   <br>   O     1.012700000   0.512700000   0.237300000   <br>   O     0.512700000   1.012700000   0.237300000   <br>   O     0.512700000   0.512700000  -0.262700000   <br>   O    -0.262700000   0.237300000   0.237300000   <br>   O     0.237300000  -0.262700000   0.237300000   <br>   O     0.237300000   0.237300000  -0.262700000   <br>   O     0.262700000   0.487300000   0.487300000   <br>   O     0.762700000  -0.012700000   0.487300000   <br>   O     0.762700000   0.487300000  -0.012700000   <br>   O    -0.012700000   0.762700000   0.487300000   <br>   O     0.487300000   0.262700000   0.487300000   <br>   O     0.487300000   0.762700000  -0.012700000   <br>   O    -0.012700000   0.487300000   0.762700000   <br>   O     0.487300000  -0.012700000   0.762700000   <br>   O     0.487300000   0.487300000   0.262700000   <br>   O     0.262700000   0.762700000   0.762700000   <br>   O     0.762700000   0.262700000   0.762700000   <br>   O     0.762700000   0.762700000   0.262700000<br clear="all"><div><div><div><div><br>-- <br><div class="gmail_signature"><div>Máximo RamÃrez<br></div><div>Physics Degree<br></div><div>Universidad Autónoma de Santo Domingo<br></div></div>
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