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<div dir="ltr">I had a look at the wiki page. This is exactly what mstar computes, except that it does not rely on a parabolic fit. Instead, the effective masses are obtained from perturbation theory. The result should be equivalent if the perturbation sum
is converted. It is then up to the user to identify the band(s) and k-point(s) of interest. If multiple valleys lie within an energy window of order k_B*T, any weighting and averaging over their contributions is outside the scope of mstar.</div>
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<div dir="ltr">Oleg<br>
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<blockquote type="cite">On Apr 9, 2026, at 05:11, Laurence Marks <laurence.marks@gmail.com> wrote:<br>
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<div>I am referring to the standard definition of effective masses for the CB & VB, e.g. <a href="https://en.wikipedia.org/wiki/Effective_mass_(solid-state_physics)" target="_blank" rel="noreferrer">https://en.wikipedia.org/wiki/Effective_mass_(solid-state_physics)</a>.
This is the tensor at the VB edge for holes and the CB edge for electrons.</div>
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<div dir="auto">From what I can see one has to take the mstar output, do a seperate spaghetti type analysis to find the k-points for the LUMO/HOMO, then extract those by hand from the mstar data dump with, perhaps, some Fermi-Dirac averaging for STP, TEMPS
Mermin functional. (There might be a cleaner method than spaghetti to find the HOMO/LUMO k-points.)</div>
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<div data-smartmail="gmail_signature">___<br>
Emeritus Professor Laurence Marks (Laurie)<br>
Department of Materials Science and Engineering, Northwestern University<br>
<a href="http://www.numis.northwestern.edu" target="_blank" rel="noreferrer">www.numis.northwestern.edu</a><br>
"Research is to see what everybody else has seen, and to think what nobody else has thought" Albert Szent-Györgyi</div>
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