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<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">Dear all users,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">I am currently trying to relax a methylammonium lead iodide CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> structure which has tetragonal structure I4/mcm. Thus, in my input
 file, I select ibrav = 7 (body centred teragonal). However, as I visualise the input and output on Xcrysden, the unit cell becomes orthorhombic. Why is that?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">&CONTROL<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                       title = 'MAPI' ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                 calculation = 'relax' ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                restart_mode = 'from_scratch' ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                      outdir = './' ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                  pseudo_dir = './' ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                      prefix = 'CH3NH3PbI3' ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">/<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">&SYSTEM<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                       ibrav = 7,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                   A = 8.83920,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                   C = 12.6948,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                         nat = 12,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                        ntyp = 5,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                     ecutwfc = 80 ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                       ecutrho = 800,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">/<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">&ELECTRONS<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">            electron_maxstep = 5000 ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                    conv_thr = 1.0d-6 ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                 mixing_beta = 0.3 ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">/<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">&IONS<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">                ion_dynamics = 'bfgs' ,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">/<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">ATOMIC_SPECIES<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    C   12.01070  c_pbesol_v1.2.uspp.F.UPF
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    H    1.00794  H.pbesol-rrkjus_psl.0.1.UPF
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    N   14.00670  N.pbesol-theos.UPF
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">   Pb  207.20000  Pb.pbesol-dn-kjpaw_psl.0.2.2.UPF
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    I  126.90450  i_pbesol_v1.uspp.F.UPF
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">ATOMIC_POSITIONS alat
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">   Pb      0.000000000    0.000000000    0.500000000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    I      0.000000000    0.000000000    0.250000000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    I      0.294200000    0.205800000    0.500000000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    I     -0.294200000   -0.207600000    0.500000000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    C      0.544000000    0.921000000    0.784000000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    H      0.609200000    1.002100000    0.769900000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    H      0.557300000    0.845500000    0.724600000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    H      0.551500000    0.875200000    0.864300000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    N      0.389000000    0.987000000    0.767000000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    H      0.324700000    0.913900000    0.730300000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    H      0.381400000    1.068100000    0.734300000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">    H      0.339300000    0.990800000    0.831000000   
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">K_POINTS automatic
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">  1 1 1   0 0 0
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">Thank you all.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">Kind regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Century Schoolbook",serif;color:#430068">Edmund Chan<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">________________________________________________</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">Edmund Chan</span></b><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">PhD Renewable Energy Student
</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">Environment & Sustainablity Institute</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">College of Engineering, Mathematics and Physical Sciences<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">University of Exeter, Penryn Campus</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">Penryn, Cornwall
</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">United Kingdom<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">TR10 9FE<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><br>
</span><i><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">Tel:</span></i><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB"> +44 (0)7455 235 701</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">Email:</span></i><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">
<a href="mailto:thc208@exeter.ac.uk"><span style="color:#183D5E;text-decoration:none">thc208@exeter.ac.uk</span></a></span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#183D5E;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#183D5E;mso-fareast-language:EN-GB">LinkedIn:
<a href="https://uk.linkedin.com/in/edmundchan1"><span style="color:#183D5E;text-decoration:none">https://uk.linkedin.com/in/edmundchan1</span></a></span></i><i><span style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#1F3864;mso-fareast-language:EN-GB"><o:p></o:p></span></i></p>
<p class="MsoNormal"><span lang="EN" style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#538135"><img border="0" width="242" height="97" style="width:2.5208in;height:1.0104in" id="_x0000_i1026" src="cid:image002.jpg@01D48037.20473080" alt="uoe"></span><i><span style="font-family:"Century Schoolbook",serif;color:#538135"><o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="color:#7030A0"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#7F7F7F;mso-fareast-language:EN-GB"><img border="0" width="392" height="19" style="width:4.0833in;height:.1979in" id="Picture_x0020_1" src="cid:image003.gif@01D48035.475E6E60" alt="cid:image002.gif@01D2F1A2.9AF74CE0"></span><span style="color:#7030A0"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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