What's the point of using extremely denser k-grid for extracting curvature effective masses? I saw in some publications that they use extremely dense k-grid for band structure calculations for reliable effective masses. However, in some publications they just extract effective masses from a band structure that determined with relatively coarse k-grid. I could not find so many information about effective mass convergence. Is it something really reliable? Thanks for your comments
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$\begingroup$ +1 but what do you mean by "different" question? Where is the first one? Why are you using an unregistered account? $\endgroup$– Nike DattaniOct 7, 2021 at 20:12
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$\begingroup$ By different question I mean it's an unique question that was not asked before. I saw that I can ask a question as a guest and I saw that it was easy $\endgroup$– JeremyOct 7, 2021 at 20:20
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2$\begingroup$ I think that as the effective mass is calculated numerically from the second derivative of E with respect to k, a better quality for E(k) will imply a better calculated effective mass. $\endgroup$– Camps ♦Oct 7, 2021 at 20:33
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The effective mass is related to the second derivative of the E-k curve as
So an accurate value of effective mass requires an accurate dispersion curve at all k points. If enough k values are not taken to plot the curve, plotting tools will interpolate the values to have a smooth curve, and the values may vary significantly from the actual values. This may lead to an inaccurate value of effective mass in those regions of brillouin zone.
