<div dir="ltr">Dear Ari,<br><br>Sorry, I didn't mention that I also tried by fixing coordinate of O_ad at a bridge position.<br>It resulted the Pt atoms moving, in such way that O_ad becomes three-fold site(either fcc or hcp).<br><br>With best regards<br>Venkataramana Imandi<br>Postdoctoral fellow<br>IIT Madras, India.<br><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Apr 10, 2018 at 2:44 PM, Venkataramana Imandi <span dir="ltr"><<a href="mailto:venkataramana.imandi@gmail.com" target="_blank">venkataramana.imandi@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br clear="all">Dear QE community,<br><br>I am a new user of Quantum espresso simulation package. I installed 6.2.1 Quantum espresso in the Linux-X86_64-INTEL-MPI. I want to find out the binding energy of O_ad at various sites(top,bridge,hcp and fcc) on Pt-surface and Pt-Ni alloy surface. In the beginning, i have tried on Pt-surface, and I got O_ad at top, hcp and fcc sites on Pt-surface, however, i couldn't find O_ad at bridge position.<br>I have tried all possible ways of getting O_ad at the bridge position(between Pt-Pt). None of them were given succussful results, and the resulted O_ad comes to either fcc or hcp position. All possible ways: using with and without spin-polarization, davidson diagonalization anc cg, option (nosym = .TRUE. and .FALSE.), mixing mode(plain, local-TF and TF), changing mixing-beta(0.2, 0.3 and 0.5), neutral, negative charge(-2) and different simulation setup (present 24 atoms to 48 Pt atoms). The last option, i used different pseudopotential(Pt.pw91-n-van.<wbr>UPF and O.pw91-van_ak.UPF), herein, i got error as follows (Error in scalartorealdp Too few elements found). Now i stopped trials.<br>I ask you can anyone do calculation in your simulation setup with the given input file, tell me the where the problem is. <br><br>I really thanks to you in advance for any suggestions regarding this.<br>For information, i used VASP in the last year, therein, i obtained O_ad at all sites on Pt-surface.<br><br> &control<br> calculation='relax'<br> restart_mode='from_scratch',<br> pseudo_dir = '/home2/oth/ch18ipf01/<wbr>pseudopotential2/',<br> prefix='pt'<br> tprnfor = .true.,<br> nstep = 200<br> /<br> &system<br> ibrav=0,<br> nat=25,<br> ntyp=2,<br> ! nspin = 2,<br> ! starting_magnetization(1)=0.7,<br> ecutwfc = 32.0,<br> ecutrho = 320.0,<br> occupations='smearing',<br> smearing='methfessel-paxton',<br> degauss=0.02<br> ! tot_charge = -2,<br> nosym = .TRUE.<br> /<br> &electrons<br> diagonalization='cg'<br> conv_thr = 1.0e-6<br> mixing_beta = 0.3<br> electron_maxstep = 1000<br> /<br>&ions<br>ion_dynamics='bfgs',<br> /<br>ATOMIC_SPECIES<br>Pt 195.084 Pt.pbe-nd-rrkjus.UPF<br>O 15.999 O.pbe-rrkjus.UPF<br><br>ATOMIC_POSITIONS {angstrom}<br>O 3.45091550 1.17466050 13.69732100 1 1 1<br>Pt 4.84778787 1.20016667 12.44963917 1 1 1<br>Pt 3.46185858 3.60066659 12.44963917 1 1 1<br>Pt 2.07592929 1.20016667 12.44963917 1 1 1<br>Pt 0.69000000 3.60066659 12.44963917 1 1 1<br>Pt 3.46185858 0.40000000 10.18642611 1 1 1<br>Pt 4.84778787 2.80049996 10.18642611 1 1 1<br>Pt 0.69000000 0.40000000 10.18642611 1 1 1<br>Pt 2.07592929 2.80049996 10.18642611 1 1 1<br>Pt 3.46185858 2.00033330 7.92321305 1 1 1<br>Pt 4.84778787 4.40083326 7.92321305 1 1 1<br>Pt 0.69000000 2.00033330 7.92321305 1 1 1<br>Pt 2.07592929 4.40083326 7.92321305 1 1 1<br>Pt 4.84778787 1.20016667 5.66000000 1 1 1<br>Pt 3.46185858 3.60066659 5.66000000 1 1 1<br>Pt 2.07592929 1.20016667 5.66000000 1 1 1<br>Pt 0.69000000 3.60066659 5.66000000 1 1 1<br>Pt 3.46185858 0.40000000 3.39678694 0 0 0<br>Pt 4.84778787 2.80049996 3.39678694 0 0 0<br>Pt 0.69000000 0.40000000 3.39678694 0 0 0<br>Pt 2.07592929 2.80049996 3.39678694 0 0 0<br>Pt 3.46185858 2.00033330 1.13357388 0 0 0<br>Pt 4.84778787 4.40083326 1.13357388 0 0 0<br>Pt 0.69000000 2.00033330 1.13357388 0 0 0<br>Pt 2.07592929 4.40083326 1.13357388 0 0 0<br><br>K_POINTS {automatic}<br>3 3 1 0 0 0<br>CELL_PARAMETERS {angstrom}<br>5.5437171600 0.0000000000 0.0000000000<br>0.0000000000 4.8009999000 0.0000000000<br>0.0000000000 0.0000000000 25.5792783300<br><br><br>With best regards<span class="HOEnZb"><font color="#888888"><br>Venkataramana Imandi<br>Postdoctoral fellow<br>IIT Madras, India.<br><br> <wbr> <wbr> <wbr> <wbr> <br><br><br><br></font></span></div>
</blockquote></div><br><br clear="all"><br>-- <br><div class="gmail_signature" data-smartmail="gmail_signature">venkataramana</div>
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