Dear M N H Liton,

The effective mass is determined by the band structure E(k).

It can be calculated by mij-1= (2pi/h)2 d2E/d2kij. Furthermore, it can be measured by cyclotron resonanz.

For more details about this subject, i suggest you to see links and attached file on topic.

Prof.P. Ravindran, & Carrier effective mass calculations - UiO

folk.uio.no/ravi/cutn/ccmp/9-EffectiveMass1.pdf

Effective mass in semiconductors

https://ecee.colorado.edu/~bart/book/effmass.htm

First-Principles Calculations of the Effective Mass Parameters of ...

www.sbfisica.org.br/bjp/files/v32_405.pdf

Effective mass of electrons in silicon | QuantumATK P-2019.03 ...

https://docs.quantumatk.com/.../effective_mass/effective...

best regards

Mohamed-Mourad Lafifi

Thank you very much.

I read these documents already but it is still unclear to me. I attached the Figure of Band structure here. Now, I need to how I can calculate the effective mass from this graph.@ Mohamed-Mourad Lafifi

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you could consider fitting a parabola to the band extrema but i would certainly not recommend this as a reasonable way to determine the effective masses !

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if you have such a figure showing the band structure, you certainly can find the book from which it is taken and find the correct values of the effective masses there !

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Fabrice Clerot

Thank You.

This figure in not from book. This is the band structure of compound whose properties I was calculated using first principle calculations in CASTEP code. But I can not able to find simple way to calculate the effective mass from this graph.

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in that case, you can compute the effective mass tensor according to the formula given by Mohamed-Mourad Lafifi above : compute e(dk) = E(k* + dk)-E(k*) with k* your extremum of interest and dk taking values on a 3D-grid with small steps around 0

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then you can fit a paraboloid to these data ( e(dk) ) with effective masses as parameters, taking into account the symetry constraints of your material

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