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OMEGAMAX

An additional option to control the number of included conduction and valence band pairs is OMEGAMAX. All conduction-band ($ i$) and valence-band ($ a$) pairs with an energy difference smaller than OMEGAMAX

$\displaystyle \epsilon_a - \epsilon_i
$

are included in the BSE matrix. Note that pairs must satisfy both criteria, the band "window" specified by NBANDSO and NBANDSV, as well as the OMEGAMAX criteria. If OMEGAMAX is not specified in the INCAR file, it defaults to the largest transition energy $ \max(\epsilon_a - \epsilon_i)$ of the bands included in the BSE calculation (as specified by NBANDSO and NBANDSV).

Furthermore, OMEGAMAX controls the energy window for the dielectric function written to vasprun.xml. The number of grid points is determined by the NEDOS parameter.



N.B. Requests for support are to be addressed to: vasp.materialphysik@univie.ac.at