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Dielectric constant in LOPTICS

Posted: Mon May 23, 2016 5:28 pm
by M Dave
Hi,

In LOPTICS calculation, real and imaginary parts of dielectric function are written at end of OUTCAR. My question is, is the energy written with respect to Fermi energy of the atomic system? Or fermi energy is set to zero for those values?

As I am getting real part of dielectric function not crossing x-aixs(zero energy) and is in positive quadrant, and still band structure shows metallic characteristic. Which seems contradicting.

Kindly help

Thank you.

Re: Dielectric constant in LOPTICS

Posted: Tue May 24, 2016 2:16 pm
by admin
Thank you for the notice. In the figure Dielectric Function produced by p4v
real and imaginary part of the dielectric function are interchanged.
Will be corrected.

Re: Dielectric constant in LOPTICS

Posted: Tue May 24, 2016 4:30 pm
by M Dave
Yes, that I noticed, And plotted graph in excel to check, but my question still remains same, is it from E-fermi in outcar or fermi level is set to zero. Would be great if fixed in p4vasp.
Thank you.

Re: Dielectric constant in LOPTICS

Posted: Wed May 25, 2016 9:03 am
by admin
Fermi level is set to zero.
Which data have you plotted in excel (vasprun.xml, OUTCAR)?

Re: Dielectric constant in LOPTICS

Posted: Wed May 25, 2016 9:33 am
by M Dave
I plotted data from OUTCAR. Is fermi energy set to zero there too?