ELPH_SELFEN_MU
ELPH_SELFEN_MU = [real array]
Default: ELPH_SELFEN_MU = 0.0
Description: list of chemical potentials at which to compute the electron-phonon self-energy and transport coefficients.
Each chemical potential specified in the list will be added to the Fermi energy determined for the k point grid KPOINTS_ELPH. This Fermi energy might be different from the one determined in the self-consistent calculation if the k point meshes or ELPH_ISMEAR is different from ISMEAR. The Fermi energy from the self-consistent and non-self-consistent calculations can be read from the OUTCAR file. For example
$ grep "Fermi energy" OUTCAR Fermi energy: 3.5134142202 Fermi energy: 3.5314189274 eV (dense k-point grid)
In this example, ELPH_SELFEN_MU = 0.1 means that the chemical potential will be set to 3.5314189274+0.1 eV.
This can be verified Chemical potential calculation section of the OUTCAR file.
Number of electrons per cell
----------------------------
T= 0.00000000 18.00000452
T= 100.00000000 18.00000536
T= 200.00000000 18.00000792
T= 300.00000000 18.00001223
T= 400.00000000 18.00001792
T= 500.00000000 18.00002315
----------------------------
Chemical potential
----------------------------
T= 0.00000000 3.63141893
T= 100.00000000 3.63141893
T= 200.00000000 3.63141893
T= 300.00000000 3.63141893
T= 400.00000000 3.63141893
T= 500.00000000 3.63141893
----------------------------
For each of these chemical potentials and temperatures, the number of electrons per cell is computed and reported. These, in turn, can be converted to a carrier density by dividing be the volume of the unit cell. If more than one value is present in ELPH_SELFEN_MU, more columns are added to the list of chemical potentials above and more instances of the electron self-energy due to electron-phonon coupling accumulators are created. The number of rows is set by the list of temperatures in ELPH_SELFEN_TEMPS.
Alternatively, one can specify the carrier density in units of by using the ELPH_SELFEN_CARRIER_DEN tag.