Dear users,<br>I work on ZnS, I faced with a problem. When i use a unit cell with 2 atom every things is OK and the bandstructure has a very good agreement with previous calculation but when i use bigger unit cell every things go wrong, Where is the problem of my calculation?<br>
I set my input files for a unit cell with 2 & 16 atoms at below.<br><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Cadvine%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CDOCUME%7E1%5Cadvine%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CDOCUME%7E1%5Cadvine%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>
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<p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><span dir="ltr" style="font-family: "Courier New";">&SYSTEM<br>
<span style=""> </span>ibrav = 2,<br>
<span style=""> </span>celldm(1)
=10.221527872,<br>
<span style=""> </span>nbnd = 50,<br>
<span style=""> </span>nat = 2,<br>
<span style=""> </span>ntyp = 2,<br>
<span style=""> </span>ecutwfc = 40 ,<br>
<span style=""> </span><span style=""> </span>ecutrho = 160 ,<span style=""> </span><br>
<span style=""> </span>occupations = 'fixed'
,<br>
<span style=""> </span>/<br>
<span style=""> </span>&ELECTRONS<br>
<span style=""> </span>conv_thr = 0.0000001
,<br>
<span style=""> </span>diago_full_acc =
.TRUE.,<br>
<span style=""> </span>/<br>
ATOMIC_SPECIES<br>
<span style=""> </span>Zn<span style="">
</span>65.409<span style=""> </span>zn_pz.upf<br>
<span style=""> </span>S<span style="">
</span>32.066<span style=""> </span><span style=""> </span>s_pz.upf<br>
ATOMIC_POSITIONS {angstrom}<br>
<span style=""> </span>Zn<span style="">
</span>0.0<span style=""> </span>0.0<span style=""> </span>0.0<br>
<span style=""> </span>S<span style="">
</span>1.352<span style=""> </span>1.352<span style=""> </span>1.352 <br>
K_POINTS {automatic}<br>
6 6 6<span style=""> </span>0<span style="">
</span>0<span style=""> </span>0</span></p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><br><span dir="ltr" style="font-family: "Courier New";"></span></p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right">
<br><span dir="ltr" style="font-family: "Courier New";"></span></p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><span dir="ltr" style="font-family: "Courier New";">%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</span></p>
<p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Cadvine%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CDOCUME%7E1%5Cadvine%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CDOCUME%7E1%5Cadvine%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>
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</p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><span dir="ltr" style="font-family: "Courier New";"><span style=""> </span>&SYSTEM<br>
<span style=""> </span>ibrav = 2,<br>
<span style=""> </span>celldm(1)
=20.446835196 ,<br>
<span style=""> </span>nbnd = 90,<br>
<span style=""> </span>nat = 16,<br>
<span style=""> </span>ntyp = 2,<br>
<span style=""> </span>ecutwfc = 40 ,<br>
<span style=""> </span><span style=""> </span>ecutrho = 160 ,<span style=""> </span><br>
<span style=""> </span>occupations = 'fixed'
,<br>
<span style=""> </span>/<br>
<span style=""> </span>&ELECTRONS<br>
<span style=""> </span>conv_thr = 0.0000001
,<br>
<span style=""> </span>diago_full_acc =
.TRUE.,<br>
<span style=""> </span>/<br>
ATOMIC_SPECIES<br>
<span style=""> </span>Zn<span style="">
</span>65.409<span style=""> </span>zn_pz.upf<br>
<span style=""> </span>S<span style="">
</span>32.066<span style=""> </span><span style=""> </span>s_pz.upf<br>
ATOMIC_POSITIONS {angstrom}<br>
<span style=""> </span>Zn<span style="">
</span>0.0<span style=""> </span>0.0<span style=""> </span>0.0<br>
<span style=""> </span>Zn<span style="">
</span>2.705<span style=""> </span>2.705<span style=""> </span>0.0<br>
<span style=""> </span>Zn<span style="">
</span>2.705<span style=""> </span>0.0<span style=""> </span>2.705<br>
<span style=""> </span>Zn<span style="">
</span>5.409<span style=""> </span>2.705<span style=""> </span>2.705<br>
<span style=""> </span>Zn<span style="">
</span>0.0<span style=""> </span>2.705<span style=""> </span>2.705<br>
<span style=""> </span>Zn<span style="">
</span>2.705<span style=""> </span>5.409<span style=""> </span>2.705<br>
<span style=""> </span>Zn<span style="">
</span>2.705<span style=""> </span>2.705<span style=""> </span>5.409<br>
<span style=""> </span>Zn<span style="">
</span>5.409<span style=""> </span>5.409<span style=""> </span>5.409<br>
<span style=""> </span>S<span style="">
</span>1.352<span style=""> </span>1.352<span style=""> </span>1.352 <br>
S<span style=""> </span>4.057<span style=""> </span>4.057<span style="">
</span>1.352<br>
S<span style=""> </span>4.057<span style=""> </span>1.352<span style="">
</span>4.057<br>
S<span style=""> </span>6.762<span style=""> </span>4.057<span style="">
</span>4.057<br>
S<span style=""> </span>1.352<span style=""> </span>4.057<span style="">
</span>4.057<br>
S<span style=""> </span>4.057<span style=""> </span>6.762<span style="">
</span>4.057<br>
S<span style=""> </span>4.057<span style=""> </span>4.057<span style="">
</span>6.762<br>
S<span style=""> </span>6.762<span style=""> </span>6.762<span style="">
</span>6.762<span style=""> </span><br>
K_POINTS {automatic}<br>
5 5 5<span style=""> </span>0<span style="">
</span>0<span style=""> </span>0</span></p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><br><span dir="ltr" style="font-family: "Courier New";"></span></p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right">
<br><span dir="ltr" style="font-family: "Courier New";"></span></p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><span dir="ltr" style="font-family: "Courier New";">Thanks for your answers</span></p>
<p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right"><span dir="ltr" style="font-family: "Courier New";">Mohsen Modarsei</span></p><p class="MsoPlainText" dir="rtl" style="text-align: left;" align="right">
<span dir="ltr" style="font-family: "Courier New";">Ferdowsi University, Iran.<br>
</span></p>
<p></p>
<br>