<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">You’re using ibrav=2, which corresponds to a cubic F (fcc). The atomic positions are in alat units. As such, as clearly stated by the error message,<div class="">atoms 1 and 2 are equivalent. Indeed, their positions are:</div><div class="">#1 --> a/2 a/2 0</div><div class="">#2 —> 0 0 0</div><div class=""><br class=""></div><div class="">Atom #1 lies at the center of a face, its position for a cubic bcc lattice is obtained by translating the lattice site at the origin (where atom #2 lies)</div><div class="">by a direct lattice vector. </div><div class=""><br class=""></div><div class="">You must specify *ONLY* inequivalent atoms, their periodic replicas cannot be included in the list of atoms. There are many other similar</div><div class="">overlapping atoms, such as</div><div class="">Ca —> 0 0 0 with Ca —> 1 1 0 or Ca —> 0 0 1.</div><div class=""><br class=""></div><div class="">Actually, to be honest, you should probably remove *ALL ATOMS BUT TWO*. Indeed, as far as I remember, CaO has a cubic bcc lattice</div><div class="">with on Ca atom in 0 0 0 and on O atom in a/2 a/2 a/2 (but please check!).</div><div class=""><br class=""></div><div class="">Provided that, in my opinion, any question is welcome, my suggestion is that you try to give a solution to error messages by yourself before</div><div class="">asking people, because what you learn if you “try to solve” is priceless if compared to what you learn if you “ask to solve”. In this respect,</div><div class="">Quantum-ESPRESSO is an exceptional lab to make experience, since especially (but not only) for the easiest tasks (such as build the band structure of</div><div class="">simple solids) many error messages are self-explanatory and user-friendly! ;-)</div><div class=""><br class=""></div><div class="">Giovanni</div><div class=""><br class=""></div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 17 Dec 2019, at 10:25, Pooja Vyas <<a href="mailto:poojavyas1251995@gmail.com" class="">poojavyas1251995@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="">Following is my input file. I obtained the atomic position using X-CrysDen. But when I run the file it shows me an error message.</div><div class=""><br class=""></div><div class="">Input file:</div><div class="">&control<br class=""> calculation = 'scf',<br class=""> prefix = '9.1334'<br class=""> tstress= .true.<br class=""> tprnfor= .true.<br class=""> outdir = '/home/userpooja/cao.oct/'<br class=""> pseudo_dir = '/home/userpooja/cao.oct/pseudo/'<br class=""> /<br class=""> &system<br class=""> ibrav = 2,<br class=""> celldm(1) = 9.1334,<br class=""> nat = 27,<br class=""> ntyp = 2,<br class=""> ecutwfc = 100,<br class="">/<br class="">&electrons<br class=""> mixing_beta = 0.7<br class=""> /<br class=""><br class="">ATOMIC_SPECIES<br class=""><br class="">Ca 40.078 Ca.pbe-nsp-van.UPF<br class="">O 15.999 O.pbe-van_ak.UPF<br class=""><br class="">ATOMIC_POSITIONS (alat)<br class="">Ca 0.5 0.5 0.0<br class="">Ca 0.0 0.0 0.0<br class="">Ca 0.5 0.0 0.5<br class="">Ca 0.0 0.5 0.5<br class="">O 0.0 0.0 0.5<br class="">O 0.5 0.5 0.5<br class="">O 0.0 0.5 0.0<br class="">O 0.5 0.0 0.0<br class="">Ca 0.5 0.5 1.0<br class="">Ca 0.0 0.0 1.0<br class="">O 0.0 0.5 1.0<br class="">O 0.5 0.0 1.0<br class="">Ca 0.0 1.0 0.0<br class="">Ca 0.5 1.0 0.5<br class="">O 0.0 1.0 0.5<br class="">O 0.5 1.0 0.0<br class="">Ca 0.0 1.0 1.0<br class="">O 0.5 1.0 1.0<br class="">Ca 1.0 0.0 0.0<br class="">Ca 1.0 0.5 0.5<br class="">O 1.0 0.0 0.5<br class="">O 1.0 0.5 0.0<br class="">Ca 1.0 0.0 1.0<br class="">O 1.0 0.5 1.0<br class="">Ca 1.0 1.0 0.0<br class="">O 1.0 1.0 0.5<br class="">Ca 1.0 1.0 1.0<br class="">K_POINTS (automatic)<br class=""> 11 11 11 1 1 1</div><div class=""><br class=""></div><div class="">Error: <br class=""></div><div class=""><br class=""> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br class=""> task # 17<br class=""> from check_atoms : error # 1<br class=""> atoms # 1 and # 2 differ by lattice vector (-1, 1, 0) in crystal axis<br class=""> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br class=""></div></div>
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<div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="text-align: start; text-indent: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="text-align: start; text-indent: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><span style="color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">-- <br class=""><br class="">Giovanni Cantele, PhD</span></div><div style="text-align: start; text-indent: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><span style="color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br class="">CNR-SPIN<br class="">c/o Dipartimento di Fisica<br class="">Universita' di Napoli "Federico II"<br class="">Complesso Universitario M. S. Angelo - Ed. 6<br class="">Via Cintia, I-80126, Napoli, Italy</span></div><div style="text-align: start; text-indent: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><span style="color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br class=""><a href="mailto:giovanni.cantele@spin.cnr.it" class="">e-mail: giovanni.cantele@spin.cnr.it</a></span></div><div style="text-align: start; text-indent: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><span style="color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""> <a href="mailto:gcantele@gmail.com" class="">gcantele@gmail.com</a><br class="">Phone: +39 081 676910<br class="">Skype contact: giocan74<br class="">Web page:<span class="Apple-converted-space"> </span></span><a href="https://sites.google.com/view/giovanni-cantele" class="">https://sites.google.com/view/giovanni-cantele</a></div></div></div></div>
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