<div dir="ltr"><div> Dear sir,<br><br>I have done calculations according your suggestions.<br>I got cohesive energy at 0 K is as follows.<br>934.7 kJ/mol<br>749.6 kJ/mol (with dispersion correction)<br>731.7 kJ/mol (with 2x2x1 k-point)<br>670.0 kJ/mol (Experiment at 0 K)<br><br>I increased plane wave cutoff to 35 to 40 Ryd., there is no change in the values.<br><br>I got surface energy as follows.<br>11.7 kJ/mol/Angstrom^2<br>28.4 kJ/mol/Angstrom^2 (with dispersion correction)<br>28.4 kJ/mol/Angstrom^2 (with 2x2x1 k-point)<br>14.9 kJ/mol/Angstrom^2 (Experiment at 0 K)<br><br>How to refine my results in such way that i will get close to experimental results by tuning input parameters. Please suggest and your information is valuable to me.<br>In single Iridium case, the input file contains additional nspin=2 and starting_magnetization(1)=1 parameters and I didn't include those parameters in the bulk Iridium case.<br>I am attaching one input file with dispersion correction as shown below.<br><br>************************************************************************<br> Structure: Ir fcc(111) ; (3x2x2) SUPER-CELL<br>------------------------------------------------------------------------<br> ------------------------------------------------------------------------<br> 6 Layers slab <br>************************************************************************<br><br>&control<br> calculation='relax',<br> prefix='ir_ch',<br> nstep=5000,<br> etot_conv_thr=1.0D-5,<br> forc_conv_thr=1.0D-4,<br> pseudo_dir = '/home/venkat/ORR1/PPS1'<br> /<br>&system<br> ibrav=0,<br> nat=72,<br> ntyp=1,<br> ecutwfc = 35.D0,<br> ecutrho=350.D0,<br> nosym=.true.,<br> occupations='smearing',<br> smearing='m-p',<br> degauss=0.07D0,<br> vdw_corr='grimme-d2'<br>/<br>&electrons<br> electron_maxstep=2000,<br> diagonalization='david',<br> mixing_beta = 0.7D0,<br> conv_thr = 1.0D-8,<br> scf_must_converge=.true. <br> mixing_mode = 'local-TF' ,<br> startingpot = 'atomic' ,<br> startingwfc = 'atomic' ,<br>/<br>&ions<br> ion_dynamics='bfgs'<br>/<br>ATOMIC_SPECIES<br>Ir 192.217 Ir.pw91-n-rrkjus_psl.0.2.3.UPF<br><br>CELL_PARAMETERS angstrom<br> 8.1437488 0.00000000 0.00000000<br> 0.0000000 9.40359112 0.00000000<br> 0.0000000 0.00000000 13.29868610<br><br>ATOMIC_POSITIONS angstrom<br>Ir 6.78645733 5.48542817 6.64934305<br>Ir 5.42916587 7.83632593 6.64934305<br>Ir 5.42916587 4.70179556 4.43289536<br>Ir 6.78645733 7.05269336 4.43289536<br>Ir 5.42916587 6.26906075 2.21644768<br>Ir 6.78645733 8.61995854 2.21644768<br>Ir 4.07187440 5.48542817 6.64934305<br>Ir 2.71458293 7.83632593 6.64934305<br>Ir 2.71458293 4.70179556 4.43289536<br>Ir 4.07187440 7.05269336 4.43289536<br>Ir 2.71458293 6.26906075 2.21644768<br>Ir 4.07187440 8.61995854 2.21644768<br>Ir 1.35729146 5.48542817 6.64934305<br>Ir 0.00000000 7.83632593 6.64934305<br>Ir 0.00000000 4.70179556 4.43289536<br>Ir 1.35729146 7.05269336 4.43289536<br>Ir 0.00000000 6.26906075 2.21644768<br>Ir 1.35729146 8.61995854 2.21644768<br>Ir 6.78645733 0.78363261 6.64934305<br>Ir 5.42916587 3.13453037 6.64934305<br>Ir 5.42916587 0.00000000 4.43289536<br>Ir 6.78645733 2.35089780 4.43289536<br>Ir 5.42916587 1.56726519 2.21644768<br>Ir 6.78645733 3.91816298 2.21644768<br>Ir 4.07187440 0.78363261 6.64934305<br>Ir 2.71458293 3.13453037 6.64934305<br>Ir 2.71458293 0.00000000 4.43289536<br>Ir 4.07187440 2.35089780 4.43289536<br>Ir 2.71458293 1.56726519 2.21644768<br>Ir 4.07187440 3.91816298 2.21644768<br>Ir 1.35729146 0.78363261 6.64934305<br>Ir 0.00000000 3.13453037 6.64934305<br>Ir 0.00000000 0.00000000 4.43289536<br>Ir 1.35729146 2.35089780 4.43289536<br>Ir 0.00000000 1.56726519 2.21644768<br>Ir 1.35729146 3.91816298 2.21644768<br>Ir 6.78645733 5.48542817 0.00000000<br>Ir 5.42916587 7.83632593 0.00000000<br>Ir 5.42916587 4.70179556 -2.21644769<br>Ir 6.78645733 7.05269336 -2.21644769<br>Ir 5.42916587 6.26906075 -4.43289537<br>Ir 6.78645733 8.61995854 -4.43289537<br>Ir 4.07187440 5.48542817 0.00000000<br>Ir 2.71458293 7.83632593 0.00000000<br>Ir 2.71458293 4.70179556 -2.21644769<br>Ir 4.07187440 7.05269336 -2.21644769<br>Ir 2.71458293 6.26906075 -4.43289537<br>Ir 4.07187440 8.61995854 -4.43289537<br>Ir 1.35729146 5.48542817 0.00000000<br>Ir 0.00000000 7.83632593 0.00000000<br>Ir 0.00000000 4.70179556 -2.21644769<br>Ir 1.35729146 7.05269336 -2.21644769<br>Ir 0.00000000 6.26906075 -4.43289537<br>Ir 1.35729146 8.61995854 -4.43289537<br>Ir 6.78645733 0.78363261 0.00000000<br>Ir 5.42916587 3.13453037 0.00000000<br>Ir 5.42916587 0.00000000 -2.21644769<br>Ir 6.78645733 2.35089780 -2.21644769<br>Ir 5.42916587 1.56726519 -4.43289537<br>Ir 6.78645733 3.91816298 -4.43289537<br>Ir 4.07187440 0.78363261 0.00000000<br>Ir 2.71458293 3.13453037 0.00000000<br>Ir 2.71458293 0.00000000 -2.21644769<br>Ir 4.07187440 2.35089780 -2.21644769<br>Ir 2.71458293 1.56726519 -4.43289537<br>Ir 4.07187440 3.91816298 -4.43289537<br>Ir 1.35729146 0.78363261 0.00000000<br>Ir 0.00000000 3.13453037 0.00000000<br>Ir 0.00000000 0.00000000 -2.21644769<br>Ir 1.35729146 2.35089780 -2.21644769<br>Ir 0.00000000 1.56726519 -4.43289537<br>Ir 1.35729146 3.91816298 -4.43289537<br><br>K_POINTS gamma<br><br></div><div>Venkataramana<br></div><div>PhD student<br></div><div>IIT Bombay<br></div><div>Mumbai<br></div><div><br><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 5, 2015 at 9:20 AM, 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"><div><div>Dear prof. Stefano,<br></div>Thank you very much for kind your help.<br></div>I will check results.<br></div><div class="gmail_extra"><div><div class="h5"><br><div class="gmail_quote">On Sat, Oct 3, 2015 at 2:59 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"><div>Dear prof. <b>STEFANO DE GIRONCOLI</b><br><br>Many thanks for spontaneous reply. On the basis of your answer, If I understood correctly, I can use nspin=2 for atomic Iridium and bulk Iridium<br>(since Iridium is paramagnetic from literature data). However, I have to specify starting_magnetization in the input file in the both atomic Iridium and bulk Iridium<br>input files. The keywords list information says that values range between -1 (all spins down for the valence electrons of atom type 'i') to 1 (all spins up). Iridium has three unpaired electrons in the spin up.<br>1. It indicates can I use starting_magnetization(1)=1 along with nspin=2.<br>2. If not that value, what value I have to use, I don't know, please suggest me.<br>3. I am not using full relativistic pseudopotential for Iridium, so, I can skip nspin=4, am I correct ?.<br><br> Please verify my assumptions.<br></div> The reply of previous thread of clean stop of running job, now I got clean stop during running job.<br><div><br></div></div><div class="gmail_extra"><div><div><br><div class="gmail_quote">On Sat, Oct 3, 2015 at 12:52 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 all<br><br>I want to calculate ground state total energy of single Iridium neutral gaseous atom.<br>The electronic configuration of Iridium atom is [Xe].4f^14.5d^7.6s^2 and in the 5d orbital, three unpaired electrons are there.<br>So, the resultant spin multiplicity is 4. Hence, in keywords list, nspin=4 or noncolin=.true. is essential.<br>I am asking that whether nspin means spin multiplicity or not ?.<br>Am i correct for determining total energy of Iridium with nspin=4 or noncolin=.true. ?<br>In case of bulk Iridium (total atoms=72), then can I skip nspin=4 or noncolin=.true. ?<br>In case of bulk Iridium electrons can get paired or not ?<br><br>Finally I want to calculate cohesive energy of bulk Iridium.<br><br>I am extremely say sorry, if questions are fundamental and trivial.<br><br>Any suggestions are appreciated and thanks in anticipated.<br><br> <br><div>venkataramana<br></div><div>PhD student<br></div><div>IIT Bombay<br></div><div>Mumbai<br></div>
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