First-principles calculations of zone-center phonons in CsB3O5: Comparison with experiment

Cesium triborate (CsB3O5) crystal is an excellent nonlinear optical material with many advantages. As one part of understanding the properties of CsB3O5, the vibrational frequencies at the Brillouin zone center are calculated using a plane-wave pesudopotential method within the framework of the local density approximation. The complete 27A+26B1+26B2+26B3 vibrational modes are assigned, graphically visualized and classified according to the vibrations of tetrahedral BO4 and (B3O6)3− ring. Comparisons with previous experimental reports are discussed in detail.