Dear Sir, Thank you for your helpful suggestions. Yes, I noticed the different RMT used for the two calculations. However, I did not set any reduction % for both the structures, and the initial RMT for both initial and final structures were the same. I will make sure to use the same RMT and run the calculations.
RKmax was set to 7, but I will try with 5.5 to 6.5. Yes, you are right, I started with GPAW calculations and took the optimized structures from there. These were just for checking whether I can compare the energy difference. Okay, I will do volume optimization with Win2k and make a supercell as you suggested and I can run with Win2k. Thank you, Gargee On Wed, 11 May 2022 at 19:29, Laurence Marks <laurence.ma...@gmail.com> wrote: > Oops, I missed the RMTs -- as almost always, Peter is right. > > N.B., In this case the constraints mode should work. If you run into > problems contact Peter or me -- this mode is still a bit experimental, not > automated. > > --- > Professor Laurence Marks > Department of Materials Science and Engineering > Northwestern University > www.numis.northwestern.edu > "Research is to see what everybody else has seen, and to think what nobody > else has thought" Albert Szent-Györgyi > > On Wed, May 11, 2022, 12:20 PM Peter Blaha <pbl...@theochem.tuwien.ac.at> > wrote: > >> Well, the main explanation is quite simple: Of course you have to use >> IDENTICAL RMTs for the 2 calculations. >> >> I can see 1.97 and 2.23 for Ru and 1.61 and 1.17 for N. >> >> This is as if you would use 2 different pseudopotentials and compare the >> energies. >> >> Since the N2 forces you to use small N spheres, you have to use them >> allways. The Ru should be chosen according to the minimum distances. >> Everything between 2.0 and 2.2 is probably fine. >> >> I'd even start with RKmax=5.5, but eventually increase it to 6 or 6.5 >> later to check if the total energy difference remains constant. >> >> In addition your cell is "funny". Why would you use such a rectangular >> cell with 20 and 10 bohr ??? >> >> And, as already mentioned by L.Marks, in WIEN2k it is much more efficient >> to use slabs with inversion symmetry, which can be easily obtained by >> putting the N atoms on both sides of the slab. >> >> You probably started with a GPAW structure, but WIEN2k has very nice >> tools to make such calculations. >> >> You should first optimize the bulk Ru structure (at least the volume). >> Using the lowest energy structure you can easily create surface slabs >> with x supercells (to start with I'd suggest a 3x3x2 or 3x3x3 >> supercell), and then put a N2 molecule by hand on both sides of the slab >> keeping inversion symmetry. >> >> run_law -fc 10; save unrelaxed; run_lapw -min; save relaxed >> >> In the same directory, you could now >> >> i) manually move the 2 N atoms apart and do the same steps as before >> >> ii) use the "constraints" option of mixer to increase the N-N distance to >> a large (desired) value. This option even allows you to get the barrier >> height, not just the energy of the starting and final structures. It may >> need some fine-tuning of some input parameters, but when you watch the N-N >> distances (and the energies) during the run you should be able to make it. >> >> Regards >> >> Peter Blaha >> Am 11.05.2022 um 08:57 schrieb Gargee Bhattacharyya: >> >> Dear Developers, >> >> I am a new user of WIEN2k. I am using WIEN2k version 18.2 running on >> slurm cluster. I am using the following command in my slurm job script: >> >> *run_lapw -NI -ec 0.0001 -cc 0.01 >& job_stats.txt* >> >> >> I am trying to compare barrier height for N2 dissociation on the Ru >> (0001) surface. Using GPAW, previously I have optimized N2 adsorbed Ru slab >> with N-N distance 1.242 Å and 2N adsorbed Ru slab with N-N distance 2.701 >> Å using K mesh 3*6*1. I have calculated the energy difference as: *1.39 >> eV.* My question is: >> >> 1. When I am running scf calculation with the optimized structures and >> comparing the energy difference, I am not getting the same. I have used the >> same two structures and used 3*6*1 non shifted K mesh. The total energy >> difference I found was : 0.0416 Ry = *0.57 eV* >> I am using non-spin polarized calculations and using LDA exchange >> functional. >> >> The initial structure (N2 adsorbed Ru) and final structure (2N adsorbed >> Ru) are attached herewith. >> >> It would be helpful if you let me know whether I have done anything wrong >> in the calculation so that I can compare the energy difference GPAW and >> Win2k. >> >> >> Kind regards >> Gargee >> >> >> >> -- >> Kind regards >> Gargee Bhattacharyya >> Postdoctoral Fellow >> Department of Physics and Astronomy >> Aarhus University >> Ny Munkegade 120 >> 8000 Aarhus C >> Denmark >> >> >> >> _______________________________________________ >> Wien mailing >> listw...@zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> >> <https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!FIUnb7Nr6G0Y1W2rP5AoEoiwYxV6eUaC2fQ5aihHUEIlsVwb3decKh3SySxdiF2N0dSZkw$> >> SEARCH the MAILING-LIST at: >> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html >> <https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!FIUnb7Nr6G0Y1W2rP5AoEoiwYxV6eUaC2fQ5aihHUEIlsVwb3decKh3SySxdiF0wSjDKxA$> >> >> -- >> ----------------------------------------------------------------------- >> Peter Blaha, Inst. f. Materials Chemistry, TU Vienna, A-1060 Vienna >> Phone: +43-158801165300 >> Email: peter.bl...@tuwien.ac.at >> WWW: http://www.imc.tuwien.ac.at >> <https://urldefense.com/v3/__http://www.imc.tuwien.ac.at__;!!Dq0X2DkFhyF93HkjWTBQKhk!FIUnb7Nr6G0Y1W2rP5AoEoiwYxV6eUaC2fQ5aihHUEIlsVwb3decKh3SySxdiF2bltB8Zg$> >> WIEN2k: http://www.wien2k.at >> <https://urldefense.com/v3/__http://www.wien2k.at__;!!Dq0X2DkFhyF93HkjWTBQKhk!FIUnb7Nr6G0Y1W2rP5AoEoiwYxV6eUaC2fQ5aihHUEIlsVwb3decKh3SySxdiF1K5XP_tQ$> >> ------------------------------------------------------------------------- >> >> _______________________________________________ >> Wien mailing list >> Wien@zeus.theochem.tuwien.ac.at >> >> https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!FIUnb7Nr6G0Y1W2rP5AoEoiwYxV6eUaC2fQ5aihHUEIlsVwb3decKh3SySxdiF2N0dSZkw$ >> SEARCH the MAILING-LIST at: >> https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!FIUnb7Nr6G0Y1W2rP5AoEoiwYxV6eUaC2fQ5aihHUEIlsVwb3decKh3SySxdiF0wSjDKxA$ >> > _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html > -- Kind regards Gargee Bhattacharyya Postdoctoral Fellow Department of Physics and Astronomy Aarhus University Ny Munkegade 120 8000 Aarhus C Denmark
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