Verifying the Experimental Hyperpolarizabilities of Organic Molecules Using Density Functional Theory

Recently, several evolutionary calculations have searched for organic molecules with very large molecular hyperpolarizabilities. These molecules are potentially useful as the building blocks of nonlinear optical devices. To date, all these evolutionary calculations have employed semiempirical methods because such methods can quickly calculate the hyperpolarizability of large molecules. Many papers in the literature suggest that the B3LYP density functional can produce molecular hyperpolarizabilities that are in good agreement with experiment. In this poster, we compare several molecules for which experimental hyperpolarizabilities are known with values we have computed using the B3LYP functional and various basis sets. We also compare our values with those obtained using the semiempirical program MOPAC to determine if B3LYP could become a viable basis for evolutionary calculations.