Theoretical study of the electronic (hyper)polarizabilities of amino acids in gaseous and aqueous phases

Static electronic dipole polarizability, first- and second-order hyperpolarizabilities of the 20 naturally occurring amino acids have been computed in the gas phase and water solution at the HF and MP2 levels with the aug-cc-pVDZ basis set. Electron correlation and solvent effects are significant for all the response electric properties, while the structure has a noticeable impact only for the polarizability anisotropy and first-order hyperpolarizability. For the series of aliphatic amino acids the second-order hyperpolarizability is linearly related to the polarizability and number of electrons.