Lyddane-Sachs-Teller-Relation

The Lyddane -Sachs -Teller relation ( also LST- relation) determines the ratio of the natural frequency of the longitudinal optical lattice vibration ( phonon ) an ionic crystal to the natural frequency of the transverse optical lattice vibration for which equals the ratio of the static permittivity (often ) to the permittivity for frequencies of the visible range (often ) is.

The Lyddane -Sachs -Teller relation is named after Russell Hancock Lyddane (1913-2001, physicist ), Edward Teller (1908-2003, physicist ) and Robert Green Sachs (1916-1990, physicist ).