Computational studies of the nonlinear optical properties of organometallic complexes

Computational methods for calculating the molecular nonlinear optical (NLO) properties of molecules are reviewed, with an emphasis on clarifying the strengths and weaknesses of the various approaches. A brief introduction to the theory of NLO effects is provided, and a summary of the key experimental techniques for the determination of molecular first hyperpolarizabilities is included, with discussion of their advantages and disadvantages. Applications of semi-empirical methods and density functional theory in developing structure–quadratic NLO property relationships for organometallic complexes (and particularly metal alkynyl complexes) are reviewed.