<html><head></head><body><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div><g class="gr_ gr_5 gr-alert gr_gramm gr_inline_cards gr_run_anim Punctuation only-ins replaceWithoutSep" id="5" data-gr-id="5">Thanks</g> Sir for the detailed reply,<br><div><br><div><div>Let me do a set of calculation according to your suggestions.<br>Get back to you soon with results.<br></div><div><br><div>Regards<br>Chin S.<br></div></div></div></div></div>
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On Tuesday, 24 April, 2018, 11:22:55 AM IST, Peter Blaha <pblaha@theochem.tuwien.ac.at> wrote:
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<div><div dir="ltr">I do not find much sense in the data you sent ???<br clear="none"><br clear="none">When you want to calculate the O2 binding energies, the RMTs and RKmax <br clear="none">values of O and O2 need to be IDENTICAL. And yes, break a bit the <br clear="none">symmetry (use slightly different a,b,c) to get the lowest energy for <br clear="none">atoms according to Hunds rule.<br clear="none">---------------------------------------------<br clear="none"><br clear="none">If you want to calculate cohesive/formation energies, you must use <br clear="none">identical RMTs and "equivalent RKmax".<br clear="none"><br clear="none">So for a Me_xO_y compound, you would first optimize the structure. <br clear="none">Optimization in genergal involves lattice parameter (at least voluem) <br clear="none">AND internal positions (forces).<br clear="none">Then you need to calculate the O2 energy and the Me (typical this is the <br clear="none">metallic phase of this element, like bcc Fe or fcc Al,...).<br clear="none"><br clear="none">To do so, you need to use a small RMT for O2 because of the samll bond <br clear="none">length. Optimize the O2-distance eg. with 1 k-point and RMT 1.2 and <br clear="none">RKMAX 5.5.<br clear="none"><br clear="none">Then repeat your Me-O compound (in the relaxed minimum structure) with <br clear="none">this same O-RMT (1.2) and also RKmax=5.5 (but a good k-mesh).<br clear="none"><br clear="none">Finally do the Me phase (with the same Me-RMT as in your compound) and a <br clear="none">RKmax= 5.5 / 1.2 * RMT(Me) !!!!!<br clear="none"><br clear="none">Form the energy difference to find the cohesive energy.<br clear="none"><br clear="none">Now repeat the O2, MeO and Me calculations, where you increase RKmax <br clear="none">from 5.5 to eg. 6.0. Form again the difference. If it is stable, you are <br clear="none">done, if not, increase RKMax again (6.6 or 7, depends also on your Me <br clear="none">and compound) until you get a stable cohesive energy.<br clear="none"><br clear="none">PS: When increasing RKmax, check the forces on the atoms if they remain <br clear="none">small (usually they do unless you started much too small).<br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none">Am 23.04.2018 um 12:14 schrieb chin Sabsu:<br clear="none">> Dear Sir,<br clear="none">> I am thankful for the confirmation of the state of O2 molecule.<br clear="none">> <br clear="none">> I am tried to reproduce some results for oxygen deficient system but I <br clear="none">> see from my data that my system is not stable.<br clear="none">> <br clear="none">> I started from the given lattice parameters, exact functionals,(GGA, as <br clear="none">> suggested in the paper) rmt k-mesh etc.<br clear="none">> <br clear="none">> The authors did not mention anything about how they have calculated the <br clear="none">> formation energy and atomization energy. In my previous post your reply <br clear="none">> with some notes, I followed the same data to simulate ground state <br clear="none">> energy of O2 and O but still am not getting the reasonable results.<br clear="none">> <br clear="none">> As I used data for O2 from FAQ and also tried according to the <br clear="none">> information given in the literature paper.<br clear="none">> <br clear="none">> I see there should not be any issue in calculating the O2 energy.<br clear="none">> <br clear="none">> <br clear="none">> My doubt is somewhere in the calculation of O (-sp) with below data:<br clear="none">> <br clear="none">> <br clear="none">> <br clear="none">> Title<br clear="none">> F LATTICE,NONEQUIV.ATOMS: 1<br clear="none">> MODE OF CALC=RELA unit=bohr<br clear="none">> 28.345900 28.345900 28.345900 90.000000 90.000000 90.000000<br clear="none">> ATOM 1: X=0.00000000 Y=0.00000000 Z=0.00000000<br clear="none">> MULT= 1 ISPLIT= 2<br clear="none">> O NPT= 781 R0=0.00010000 RMT= 1.65000 Z: 8.000<br clear="none">> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000<br clear="none">> 0.0000000 1.0000000 0.0000000<br clear="none">> 0.0000000 0.0000000 1.0000000<br clear="none">> 48 NUMBER OF SYMMETRY OPERATIONS<br clear="none">> <br clear="none">> <br clear="none">> <br clear="none">> and<br clear="none">> O<br clear="none">> He 3<br clear="none">> 2,-1,1.0 N<br clear="none">> 2,-1,1.0 N<br clear="none">> 2, 1,1.0 N<br clear="none">> 2, 1,1.0 N<br clear="none">> 2,-2,2.0 N<br clear="none">> 2,-2,0.0 N<br clear="none">> ****<br clear="none">> **** END of input (instgen_lapw)<br clear="none">> <br clear="none">> <br clear="none">> below are data from O2 and O-atom with GGA<br clear="none">> <br clear="none">> O_atom_rmt_1.75_rkmax_7 -149.86322972<br clear="none">> O_atom_rmt_1.1_rmkax_5.5 -150.0869798<br clear="none">> O2_mol_bondlength_1.21_rkmax_5.5 -300.1077091<br clear="none">> [O2_mol_1.21]\2 -150.05385455<br clear="none">> O3_mol_1.21 -450.16156365<br clear="none">> O2_mol_bondlength_1.219_rkmax_4.6 -299.95534741<br clear="none">> [O2_mol_1.219]\2 -149.977673705<br clear="none">> O3_mol_1.219 -449.933021115<br clear="none">> <br clear="none">> <br clear="none">> <br clear="none">> In his previous post in response of my query, Prof. Alay advice about <br clear="none">> calculating the ground state energy of O-atom by considering O atom cell <br clear="none">> as orthorhombic to avoid any issue occurring from the occupancy of <br clear="none">> P-states of O-atom. His statement is quoted below:<br clear="none">> <br clear="none">> <br clear="none">> "Computing the atomic energies of atoms like N and P in an FCC cell is <br clear="none">> ok, however for O atom the high symmetry of the FCC cell results in 1/3 <br clear="none">> occupancies (for the 4th p electron of O) in the spin down case. Only using<br clear="none">> <br clear="none">> a lower symmetry cell (orthorhombic) for O atom eliminates this issue."<br clear="none">> <br clear="none">> <br clear="none">> Could you please advise me whether my above data looks good or not.<br clear="none">> <br clear="none">> If I have to follow the suggestion advanced by Prof. Alay, then how to <br clear="none">> make an Orthorhombic cell for O-atom?<br clear="none">> <br clear="none">> I have done three calculations for three materials but I am not getting <br clear="none">> the atomization and formation energy of O2 while the author reported <br clear="none">> similar statements in his papers.<br clear="none">> <br clear="none">> <br clear="none">> Please help me to simulate the ground state energy of O2 and O taking <br clear="none">> care of occupancy of P orbitals.<br clear="none">> <br clear="none">> Please let me know what additional information I can provide.<br clear="none">> <br clear="none">> <br clear="none">> thank you very much for a big help.<br clear="none">> <br clear="none">> Chin S.<br clear="none">> <br clear="none">> <br clear="none">> <br clear="none">> <br clear="none">> On Monday, 23 April, 2018, 10:32:22 AM IST, Peter Blaha <br clear="none">> <<a shape="rect" ymailto="mailto:pblaha@theochem.tuwien.ac.at" href="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a>> wrote:<br clear="none">> <br clear="none">> <br clear="none">> This is the configuration for a spin-polarized O atom.<br clear="none">> <br clear="none">> And yes, this starting configuration will lead to the triplet state of<br clear="none">> O2 (when you perform spin-polarized calculations.)<br clear="none">> <br clear="none">> Am 22.04.2018 um 08:16 schrieb chin Sabsu:<br clear="none">> > Dear Users,<br clear="none">> ><br clear="none">> ><br clear="none">> > Could you please advice me whether below *.inst form O2 in triplet<br clear="none">> > state? three e- in dn and one e- in up state?<br clear="none">> ><br clear="none">> ><br clear="none">> > O<br clear="none">> > He 3<br clear="none">> > 2,-1,1.0 N<br clear="none">> > 2,-1,1.0 N<br clear="none">> > 2, 1,1.0 N<br clear="none">> > 2, 1,1.0 N<br clear="none">> > 2,-2,2.0 N<br clear="none">> > 2,-2,0.0 N<br clear="none">> > ****<br clear="none">> > **** END of input (instgen_lapw)<br clear="none">> ><br clear="none">> ><br clear="none">> > Thanks and best regards,<br clear="none">> ><br clear="none">> > Chin S.<br clear="none">> <br clear="none">> ><br clear="none">> ><br clear="none">> > _______________________________________________<br clear="none">> > Wien mailing list<br clear="none">> > <a shape="rect" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at" href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a shape="rect" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at" href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br clear="none">> > <a shape="rect" href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br clear="none">> > SEARCH the MAILING-LIST at: <br clear="none">> <a shape="rect" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html" target="_blank">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html</a><br clear="none">> ><br clear="none">> <br clear="none">> -- <br clear="none">> --------------------------------------------------------------------------<br clear="none">> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna<br clear="none">> Phone: +43-1-58801-165300 FAX: +43-1-58801-165982<br clear="none">> Email: <a shape="rect" ymailto="mailto:blaha@theochem.tuwien.ac.at" href="mailto:blaha@theochem.tuwien.ac.at">blaha@theochem.tuwien.ac.at</a> <mailto:<a shape="rect" ymailto="mailto:blaha@theochem.tuwien.ac.at" href="mailto:blaha@theochem.tuwien.ac.at">blaha@theochem.tuwien.ac.at</a>> <br clear="none">> WIEN2k: <a shape="rect" href="http://www.wien2k.at" target="_blank">http://www.wien2k.at</a><br clear="none">> WWW:<br clear="none">> <a shape="rect" href="http://www.imc.tuwien.ac.at/tc_blaha------------------------------------------------------------------------- " target="_blank">http://www.imc.tuwien.ac.at/tc_blaha------------------------------------------------------------------------- </a><br clear="none">> <br clear="none">> <br clear="none">> _______________________________________________<br clear="none">> Wien mailing list<br clear="none">> <a shape="rect" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at" href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a shape="rect" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at" href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br clear="none">> <a shape="rect" href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br clear="none">> SEARCH the MAILING-LIST at: <br clear="none">> <a shape="rect" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html" target="_blank">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html</a><div class="yqt6630810485" id="yqtfd34817"><br clear="none">> <br clear="none">> <br clear="none">> <br clear="none">> _______________________________________________<br clear="none">> Wien mailing list<br clear="none">> <a shape="rect" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at" href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br clear="none">> <a shape="rect" href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br clear="none">> SEARCH the MAILING-LIST at: <a shape="rect" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html" target="_blank">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html</a><br clear="none">> <br clear="none"><br clear="none">-- <br clear="none">--------------------------------------------------------------------------<br clear="none">Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna<br clear="none">Phone: +43-1-58801-165300 FAX: +43-1-58801-165982<br clear="none">Email: <a shape="rect" ymailto="mailto:blaha@theochem.tuwien.ac.at" href="mailto:blaha@theochem.tuwien.ac.at">blaha@theochem.tuwien.ac.at</a> WIEN2k: <a shape="rect" href="http://www.wien2k.at" target="_blank">http://www.wien2k.at</a><br clear="none">WWW: <br clear="none"><a shape="rect" href="http://www.imc.tuwien.ac.at/tc_blaha------------------------------------------------------------------------- " target="_blank">http://www.imc.tuwien.ac.at/tc_blaha------------------------------------------------------------------------- </a><br clear="none"><br clear="none">_______________________________________________<br clear="none">Wien mailing list<br clear="none"><a shape="rect" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at" href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br clear="none"><a shape="rect" href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br clear="none">SEARCH the MAILING-LIST at: <a shape="rect" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html" target="_blank">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html</a><br clear="none"></div></div></div>
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