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Dear Wu,
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<div>I can answer some of your queries:</div>
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<div>1. I believe the difference should be related to whether you are referring the conductance (units of S) or conductivity (units of S/m).</div>
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<div>2. Try setting fermi_energy_step in the input file. The default value is 0.01 eV.</div>
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<div>3. I¡¯m not familiar with the VASP interface so I won¡¯t speculate on why it might not be writing those files. But in case you had not realised, with wannier90 v2.0.0 there are now two executables that you can compile: one a serial executable (wannier90.x,
obtained via ¡°make wannier¡±) for first performing the spread minimisation, calculating the Wannier functions, and a few other things (i.e. pretty much everything that wannier90-1.2 does); the other a parallel executable (postw90.x, obtained via ¡°make post¡±)
that calculates several further properties (DoS, Berry curvature etc - see the user guide for full details.)</div>
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<div>And finally, please don¡¯t forget to sign off with your affiliation!</div>
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<div>Best wishes,</div>
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<div>Arash</div>
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<div>¡ª</div>
<div>Dr Arash Mostofi ¡ª <a href="http://www.mostofigroup.org">www.mostofigroup.org</a></div>
<div>Imperial College London</div>
<div>Director, Thomas Young Centre @Imperial</div>
<div>Assistant Director, CDT in Theory & Simulation of Materials</div>
<div>Warden, Wilkinson & Weeks Hall</div>
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<div>On 3 Nov 2014, at 20:06, Menghao Wu <<a href="mailto:wmh1987@mit.edu">wmh1987@mit.edu</a>> wrote:</div>
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<div style="direction: ltr; font-family: Tahoma; font-size: 10pt;">Dear Wannier developers & experts,
<div>I am trying to calculate quantum anomalous Hall conductivity by using VASP+Wannier90.x+postw90.x, may I ask some questions:</div>
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<div>1. Why the unit of ahc Anomalous Hall conductivity is S/cm? <span style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);">von Klitzing constant </span><i style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);">R</i><sub style="line-height: 1; font-size: 11px; color: rgb(37, 37, 37); font-family: sans-serif; background-color: rgb(255, 255, 255);">K</sub><span style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);"> = </span><i style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);">h</i><span style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);">/</span><i style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);">e</i><sup style="line-height: 1; font-size: 11px; color: rgb(37, 37, 37); font-family: sans-serif; background-color: rgb(255, 255, 255);">2</sup><span style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);"> =
25812.807557</span><a href="http://en.wikipedia.org/wiki/Ohm_(unit)" class="mw-redirect" style="text-decoration: none; color: rgb(11, 0, 128); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-image: none; background-color: rgb(255, 255, 255); background-position: initial initial; background-repeat: initial initial;">¦¸</a>, <span style="font-size: 10pt;">I
think the unit of </span><img src="http://upload.wikimedia.org/math/e/6/9/e691ff814e0a8f18011073388d3d60b3.png" alt=" \sigma = \frac{I_\text{channel}}{V_\text{Hall}} = \nu \; \frac{e^2}{h}, " style="font-size: 10pt;"><span style="font-size: 10pt;"> </span><span style="font-size: 10pt;"> should
be S or </span><a href="http://en.wikipedia.org/wiki/Ohm_(unit)" title="http://en.wikipedia.org/wiki/Ohm_(unit)
Ctrl+µ¥»÷´Ë¸ú×ÙÁ´½Ó" class="mw-redirect" style="text-decoration: none; color: rgb(11, 0, 128); font-family: sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-image: none; background-color: rgb(255, 255, 255); background-position: initial initial; background-repeat: initial initial;">¦¸</a>-1
in all previous report I read. Why this conductivity is S over a length?</div>
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<div>2. As I set in .win file:</div>
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<div>fermi_energy_min = -2.685</div>
<div>fermi_energy_max = -2.485</div>
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<div>berry = true</div>
<div>berry_task = ahc</div>
<div>berry_kmesh = 25 25 1</div>
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<div>In the oupt .ahc. file I get:</div>
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<div> -2.685000 -0.009966 -0.000345 -69.735021</div>
<div> -2.675000 -0.005905 -0.002186 -89.967445</div>
<div> -2.665000 -0.002600 -0.001902 -266.247099</div>
<div> -2.655000 0.002155 -0.003784 -266.146173</div>
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<div>......</div>
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<div> -2.495000 0.011176 0.013206 51.615581</div>
<div> -2.485000 0.014227 0.010831 32.024074</div>
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<div>But the grid of fermi energy is constantly 0.01eV no matter how I tune the fermi_energy min and max. I cannot find any tag in manual on making it denser. But I need a much denser plot to show the plateau of AHC. Is there any tag setup that can make it
denser£¿</div>
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<div>3. <span style="font-size: 10pt;">Seems only wannier90-2.0 has postw90.x dealing with berry curvature, but as I first run vasp, it finishes without generating *eig,*mmn files, and if I then run wannier90, .werr comes out asking for *eig, *mmn files so
I cannot continue.</span></div>
<div><span style="font-size: 10pt;"> But for wannier90-1.2, the first step by vasp will generate *eig, *mmn files and everything goes smoothly.</span></div>
<div><span style="font-size: 10pt;"> So the problem is, will it be ok I first run vasp+ wannier90.x in --1.2 version, and the use postw90.x in --2.0 version?</span></div>
<div><span style="font-size: 10pt;"> Or is there anyway to solve the problems in the first step that vaspwannier90--2.0.0 cannot generate *eig,*mmn files?</span></div>
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<div><span style="font-size: 10pt;">4. </span><span style="font-family: Helvetica, Arial, sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);">It was reported that Wannier90 can be used to calculate the edge Green¡¯s
function of the semi-infinite lattice using the recursive method:</span></div>
<div><span style="font-family: Helvetica, Arial, sans-serif; font-size: 14px; line-height: 22.3999996185303px; background-color: rgb(255, 255, 255);"> </span><font face="Helvetica, Arial, sans-serif"><span style="font-size: 14px; line-height: 22.3999996185303px;"><a href="http://pubs.acs.org/doi/full/10.1021/nl401147u">http://pubs.acs.org/doi/full/10.1021/nl401147u</a> </span></font></div>
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<div> But I cannot find such function in the manual. Is there any tag setup that can calculate edge state of semi-infinite systems?</div>
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<div>Thank you very much and your help is highly appreciated!</div>
<div>Best regards</div>
<div>Wu</div>
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