Dear wannier users, I have three questions regarding Wannier90 program. I'd appreciate it if you could share similar experiences or advice.
1. DFT Band vs. Wannier Band Energy Discrepancies When calculating the DFT band and the Wannier band and directly comparing the energies at the same k-point for each band, a difference of approximately 1.0d-1 to 1.0d-8 eV is observed. Generally, what level of error is considered "well-Wannierized"? (Of course, the k-point sampling matches. Looking at the Wannier90 tutorial file, there's a noticeable difference between the DFT band and the Wannier band plot. If it's visible in the figure, it must be a fairly large energy difference. Is this correct?) 2. Semiconductor calculations In semiconductor systems, the valence bands are often well-matched, but the conduction bands are not. What are the main causes of this problem? Also, the common advice is to "include a small range of CBM in the frozen window." Is this the right approach? 3. GW interpolation When performing GW interpolation, the example spread sometimes appears abnormally large, as shown below. Are there any practical methods or tips for reducing the spread in these situations? example) ---------- Final State WF centre and spread 1 ( 0.372766, 0.271454, 0.100115 ) 8.87768007 WF centre and spread 2 ( 0.346249, 0.302240, 0.077516 ) 8.52974539 WF centre and spread 3 ( 0.956188, -1.596142, -1.585203 ) 6.79466576 WF centre and spread 4 ( 0.846529, -1.265707, -1.314245 ) 6.88845477 WF centre and spread 5 ( -1.559035, 0.934612, -1.539765 ) 6.84836086 WF centre and spread 6 ( -1.485984, 0.895648, -1.506476 ) 6.84063641 WF centre and spread 7 ( 0.001865, -0.046586, -0.038040 ) 6.32797742 WF centre and spread 8 ( -0.015611, 0.007019, -0.016586 ) 6.19032592 WF centre and spread 9 ( 2.736587, 2.395840, 2.681191 ) 3.32470432 WF centre and spread 10 ( 2.708292, 2.346611, 2.696151 ) 3.54016326 WF centre and spread 11 ( 3.978830, 2.338176, 2.495150 ) 11.21574562 WF centre and spread 12 ( 4.065804, 2.432744, 2.491568 ) 10.51734314 WF centre and spread 13 ( 2.407247, 2.765620, 2.725119 ) 3.10145325 WF centre and spread 14 ( 2.507236, 2.783624, 2.679231 ) 2.94491143 WF centre and spread 15 ( 2.416386, 3.956995, 2.508559 ) 12.16683265 WF centre and spread 16 ( 2.547707, 3.808478, 2.527233 ) 13.94873621 WF centre and spread 17 ( 2.799901, 2.787311, 2.490126 ) 2.72683243 WF centre and spread 18 ( 2.752923, 2.802438, 2.557549 ) 2.64088968 WF centre and spread 19 ( 2.603858, 2.616160, 3.779997 ) 14.13766140 WF centre and spread 20 ( 2.670033, 2.661026, 3.723072 ) 14.56538142 WF centre and spread 21 ( 1.847802, 1.851559, 7.111413 ) 6.21201839 WF centre and spread 22 ( 1.919903, 1.792560, 7.134523 ) 6.13615812 WF centre and spread 23 ( 7.062253, 1.721907, 2.052594 ) 9.15177271 WF centre and spread 24 ( 5.666186, 0.286729, 2.746048 ) 6.62187501 WF centre and spread 25 ( 0.221796, 5.652035, 2.778891 ) 6.70473982 WF centre and spread 26 ( 1.704720, 7.043909, 2.077182 ) 8.93031270 WF centre and spread 27 ( 1.185488, 1.174497, 3.638038 ) 1.59968796 WF centre and spread 28 ( 1.185512, 1.174349, 3.638713 ) 1.60317424 WF centre and spread 29 ( 3.650511, 1.159018, 1.159550 ) 1.42725534 WF centre and spread 30 ( 3.649241, 1.159410, 1.159591 ) 1.42553039 ---------- You don't have to answer every question. Feel free to share your experiences and know-how, as it would be very helpful. Best regards, GiMyung Park Yonsei University
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