<div>Dear <span style="font-size: 12px; line-height: 18px; background-color: rgb(239, 239, 239);">Felix</span></div><div><span style="font-size: 12px; line-height: 18px; background-color: rgb(239, 239, 239);">If I am correct, PBE contains self-interaction error, that means it may give a wrong number when you use it to calculate a single electron system such as hydrogen. Mayben you could try B3LYP or HSE.</span></div><div><span style="font-size: 12px; line-height: 18px; background-color: rgb(239, 239, 239);">Best wishes</span></div><div><br></div><div><sign signid="99"><div style="color:#909090;font-family:Arial Narrow;font-size:12px"><br><br><br><br>------------------</div><div style="font-size:14px;font-family:Verdana;color:#000;"><div><div class="logo" style="width:305px;height:35px;line-height:35px;margin:20px 0 0 0;"><img src="https://exmail.qq.com/cgi-bin/viewfile?type=logo&domain=sustc.edu.cn"></div><div class="c_detail" style="margin:10px 0 0 0;"><h4 class="name" style="margin:0;font-size:14px;font-weight:bold;line-height:28px;zoom:1;">庞瑞(PANG Rui)</h4><p class="position" style="margin:0;line-height:22px;color:#a0a0a0;"></p><p class="department" style="margin:0;line-height:22px;color:#a0a0a0;">South University of Science and Technology of China/Department of Physics</p><p class="department" style="margin:0;line-height:22px;color:#a0a0a0;">No.1088,Xueyuan Road, Shenzhen,Guangdong<br></p><p class="phone" style="margin:0;line-height:22px;color:#a0a0a0;"></p></div></div></div></sign></div><div> </div><div><includetail><div> </div><div> </div><div style="font:Verdana normal 14px;color:#000;"><div style="FONT-SIZE: 12px;FONT-FAMILY: Arial Narrow;padding:2px 0 2px 0;">------------------ Original ------------------</div><div style="FONT-SIZE: 12px;background:#efefef;padding:8px;"><div id="menu_sender"><b>From: </b> "Felix Brockherde"<fbrockherde@gmail.com>;</div><div><b>Date: </b> Fri, Feb 26, 2016 09:31 PM</div><div><b>To: </b> "Pw_forum"<Pw_forum@pwscf.org>; <wbr></div><div></div><div><b>Subject: </b> [Pw_forum] Binding Energy for H2O with PAW</div></div><div> </div><div dir="ltr"><div>Dear all,</div><div><br></div>We would like to calculate the binding energy for non-equilibrium H2O geometries with PAW pseudo potentials.<br><br>The initial thought was to calculate the single-atom energies. However, for H the system becomes metallic. We used smearing but the results seem too far from the experimental value for us to use them (-0.91784682 Ry).<br><br>Now, we would like to calculate the binding energy by separating the H2O molecule as far as necessary. We would thus avoid inaccuracies caused by smearing because it is not a metallic system. However, when pulling H2O apart, the DFT calculations do not converge.<div><br></div><div>Can anybody help with either how to get the separated H2O converged or a different approach to get the binding energy with PAW pseudo potentials?</div><div><br></div><div>We used PWSCF v.5.1.1 and I attached an input file where QE does not converge.</div><div><br></div><div>Best regards,</div><div>Felix Brockherde</div><div>TU Berlin</div><div><br></div><div><div> &CONTROL</div><div> calculation = 'scf',</div><div> wfcdir = 'tmp',</div><div> pseudo_dir = '/home/user/pseudo_potentials',</div><div> tprnfor = .true.,</div><div> prefix = 'prefix',</div><div> tstress = .false.,</div><div> outdir = './',</div><div> wf_collect = .true.,</div><div> /</div><div> &SYSTEM</div><div> nat = 3,</div><div> ntyp = 2,</div><div> ecutwfc = 90,</div><div> ecutrho = 360,</div><div> celldm(1) = 30,</div><div> ibrav = 1,</div><div> /</div><div> &ELECTRONS</div><div> /</div><div>ATOMIC_SPECIES</div><div> H 1.00794 H_pbe-kjpaw_psl.0.1.UPF</div><div> O 15.9994 O_pbe-kjpaw_psl.0.1.UPF</div><div>ATOMIC_POSITIONS alat</div><div> O 0.5 0.3 0.5</div><div> H 0.5 0.7 0.3</div><div> H 0.5 0.7 0.7</div><div>K_POINTS automatic</div><div> 1 1 1 0 0 0</div></div></div>
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