  Full potential spin-polarized self-consistent electronic structure
calculation s have been performed on LaB$_{6}$, EuB$_{6}$ and YbB$_{6}$ using
Linear Muffin- Tin Orbital Method. The electronic structure of EuB$_{6}$ shows
a small overlap near the Fermi level. This is in disagreement with the recent
ARPES study. The r eflectivity spectrum shows a plasma resonance at about 0.3
eV in EuB$_{6}$. Abso rption starts at about 1.5 eV and it is due to 4$f$ to
5$d$ transition. Both the se features are reflected in the magneto-optical Kerr
spectrum. At 0.3 eV, there is a rotation of +8$^{0}$ to -10$^{0}$ and at 1.5
eV, a rotation of about 0.5$^ {0}$ occurs. The reasonable agreement with MOKE
experiment implies that the incl usion of Drude correction is absolutely
essential for the treatment of EuB$_{6}$ .
