RbPb2Br5 is a crystal composed of rubidium, lead, and bromine. It is a metal halide crystal and is used as a nonlinear optical material. RbPb2Br5 is known for its high nonlinear optical coefficients, making it suitable for use in applications such as frequency doubling, optical parametric oscillation, and other nonlinear optical processes. Additionally, its high thermal stability and good chemical resistance make it an attractive material for use in various optical and optoelectronic devices.