This proposal requests 4 days on Tosca to investigate the local structure and vibrational properties of phospors for solid state white lighting. The key objective is to investigate how the vibrational properties and in particular low-frequency vibrations couple to the materials' light-emitting efficiencies and thermal quenching. The latter is referred to as a non-radiative process that involves phonons and/or local vibrational modes, however the exact nature of these vibrational motions and the correlation to the functional properties of the materials are more or less entirely unexplored. Hence, there exists great scope for basic new science to understand the interplay between phonons and local vibrational modes and light emitting properties in phosphors. The impact of this study may therefore become very considerable.