[Wien] Plasma frequency

[delamora]

Dear WIEN2k users,

    I am trying to calculate the plasma frequency for a magnetic system.

    I find that if the calculation is with spin-orbit then the 'up' and 'dn' values are the same, so I tried the CrO2 system;


a=b=4.36A

c=2.897

angles=90

group: 136 (P 42/m n m)


This is a half metal compound, that is, there is a gap in the minority spin (in this case, in other systems the gap is in the mayority spin)


The plasma frequency squared is proportional to the electronic component of the conductivity, so the plasma frequency shoud be cero for the down spin;


runsp -orb
CrO2.outputjointup-       w_p_xx      w_p_zz    [eV]
CrO2.outputjointup-       1.4563      0.9833
CrO2.outputjointdn-       0.0000      0.0000


so far it is fine....


but when the spin-orbit coupling is includded then


runsp -orb -so
CrO2.outputjointup-       4.6663      3.5413
CrO2.outputjointdn-       4.7557      3.3685


which is inconsistent with the fact that there is a gap in the 'dn' spin


Now, the funny thing is that if I calculate with spin-orbit coupling (runsp -orb -so) from the start then the 'up' and 'dn' values are exactly the same.


Here the calculation is not very accurate, that is,

RxK=7 with 100 k-points


But with a more accurate calculation the same inconsistencies are found.


        Saludos


                        Pablo de la Mora

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