Optical Properties

This section enables the calculation of the dielectric function, which describes how a material responds to electromagnetic radiation (light). From this, properties like absorption spectra, reflectivity, and refractive index can be derived.

• Optical.Energy.Range: Defines the photon energy range for which to calculate the spectrum.
• Optical.Broaden: Applies a smearing to the calculated spectrum to simulate lifetime effects and improve visual appearance.
• Optical.Scissor: Applies a rigid energy shift ("scissor cut") to the conduction bands. This is a common ad-hoc correction for the underestimation of the band gap by standard DFT functionals.
• Optical.Mesh: Optical calculations are very sensitive to k-point sampling and typically require a much denser grid than the SCF calculation.