B3PW91

B3PW91 is a hybrid density functional theory (DFT) method used in computational chemistry to study the electronic structure of molecules and materials. It is a combination of the Becke three-parameter exchange functional (B3) and the Perdew-Wang 91 (PW91) correlation functional. The B3 component includes a mixture of exact exchange, Hartree-Fock exchange, and Becke exchange, while the PW91 component includes the Perdew-Wang 91 correlation functional. This combination aims to provide a balance between accuracy and computational efficiency, making it suitable for a wide range of applications, including the study of molecular geometries, vibrational frequencies, and electronic properties. B3PW91 has been widely used in the literature to study various chemical systems, from small molecules to complex materials. Its performance has been evaluated in numerous benchmark studies, and it has been found to provide reasonable results for many systems, although it may not be the best choice for all applications. It is important to note that the choice of functional should be based on the specific requirements of the study and the system being investigated.