Dear Prof. L. Marks, Thanks for your suggestions. Yes, WO3 is an insulator.
I am facing the same issue for WC (SG: 187). I have worked on Ni(OH)2 and ZnO surfaces and I did not face any difficulties there. Ni(OH) surface is also polar. For the present case, I do not have much choice. I was asked to provide the absorbance of some molecules on the (100) surface of WO3. The experimental group is not using any substrate/support for it. I will read up on oxide surfaces. Thank you very much, Bhamu On Fri, Jun 25, 2021 at 12:46 PM Laurence Marks <[email protected]> wrote: > N.B., your cell is polar, and you are not satisfying valence neutrality or > Pauling's rules. It will never occur in reality, and any results you obtain > with it will move science backwards. > > Read up on oxide surfaces, much is known. > > _____ > Professor Laurence Marks > "Research is to see what everybody else has seen, and to think what nobody > else has thought", Albert Szent-Györgyi > www.numis.northwestern.edu > > On Fri, Jun 25, 2021, 01:59 Laurence Marks <[email protected]> > wrote: > >> Did you check: >> a) The BVS, to ensure that you do not have a GIGO surface? >> b) Whether the system has a decent gap or not -- I believe WO3 should be >> an insulator. >> c) Whether you are satisfying valence neutrality at the surface. >> >> I expect you have a GIGO surface, 99.99% probability. You cannot just >> create an oxide supercell and expect it to lead to a realistic surface. >> Fixing layers won't help, and is flawed thinking. >> >> GIGO. >> >> _____ >> Professor Laurence Marks >> "Research is to see what everybody else has seen, and to think what >> nobody else has thought", Albert Szent-Györgyi >> www.numis.northwestern.edu >> >> On Fri, Jun 25, 2021, 01:31 Dr. K. C. Bhamu <[email protected]> wrote: >> >>> Dear Wien2k Users, >>> >>> I am trying to relax the WO3 surface structure (1x1x5 with 15 Ang >>> vacuum). The bulk structure crystallizes in 221 SG. >>> Then I created the 1x1x5 layered structure and relaxed the top two >>> layers with the bottom three layers kept fixed. >>> I see after relaxation, the top layer detached from the system (the W-O >>> bond length increased from 1.9 to 2.3 Ang), you can see from the PDF >>> provided with this email. >>> I have tried with QE as well and the same problem I faced there. >>> I am wondering if someone has faced a similar experience and would like >>> to share his/her experience with me to tackle this issue. >>> >>> I have used a different strategy: with U, with U, with dipole >>> correction, without dipole correction, vacuum up to 30Ang. >>> >>> As the bulk system is a high symmetry system, is it the reason due to >>> the symmetry? If so then how one can handle it? >>> >>> I am providing the required information here in the tar file (PLEASE >>> DOWNLOAD FROM HERE >>> <https://urldefense.com/v3/__https://we.tl/t-0vedkrUS54__;!!Dq0X2DkFhyF93HkjWTBQKhk!Day7KZQBXQaPn8HGxSpldvOiJzObtS73z_8I17izzlA5ZmuvSj27rMzSsjCo-bt6MCzNAQ$> >>> ). >>> >>> I would appreciate it if someone shares their experience with me. >>> >>> Regards >>> Bhamu >>> >>> >>> >>> >>> >>> _______________________________________________ >>> Wien mailing list >>> [email protected] >>> >>> https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!Day7KZQBXQaPn8HGxSpldvOiJzObtS73z_8I17izzlA5ZmuvSj27rMzSsjCo-btL6FGi9Q$ >>> SEARCH the MAILING-LIST at: >>> https://urldefense.com/v3/__http://www.mail-archive.com/[email protected]/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Day7KZQBXQaPn8HGxSpldvOiJzObtS73z_8I17izzlA5ZmuvSj27rMzSsjCo-btzLCeneQ$ >>> >> _______________________________________________ > Wien mailing list > [email protected] > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/[email protected]/index.html >
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