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About effective mass

cesar29
2007-09-13
2013-06-05
  • cesar29

    cesar29 - 2007-09-13

    I have calculated the effective mass for Titaniun dioxide, but I have more doubts about this calculation:

    In the file EFFMASS.OUT appears for each eigenvalue, the inverse matrix of mass, and the eigenvalues of mass for this matrix.

    Here is part of my ouput for effective mass calculation for gamma point only, but in this calculation, I obtained 30  eigenvalues and 30 effective mass tensors :

    State, eigenvalue :     30  0.3033625375

    matrix of eigenvalue derivatives with respect to k :
      0.4647995199      0.6582342860E-03  0.4786701080E-05
      0.6582342860E-03  0.4647995199      0.4786696506E-05
      0.4786701080E-05  0.4786696506E-05   2.346653532
    trace :    3.276252572

    effective mass tensor (inverse of derivative matrix) :
       2.151469532     -0.3046842627E-02 -0.4382350050E-05
    -0.3046842627E-02   2.151469532     -0.4382345850E-05
    -0.4382350050E-05 -0.4382345850E-05  0.4261387489
    trace :    4.729077813
    eigenvalues :
      0.4261387488       2.148422689       2.154516375

    (this is the last eigenvalue in the list)

    I need to obtain effective masses for the lower band of the conduction bands
    So, my question is, how I can identify which effective mass tensor (or wich eigenvalue) correspond to this band ?

     
    • exciting

      exciting - 2007-09-27

      Sorry for the delay in replying.

      The best way is to plot the band structure through the k-point you're interested in, and then count the number of valence bands up to the one you want. Then simply find that band in the EFFMASS.OUT file.

      Regards,
      Kay.

       

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