Polarizabilities and Second Hyperpolarizabilities of Hydrogen Chains Using the Spin-Component-Scaled Moller-Plesset Second-Order Method

Static longitudinal polarizabilities (alpha) and second hyperpolarizabilities (gamma) of model H-2 chains have been calculated at different ab initio levels to address the performance of the recently proposed spin-component-scaled MP2 (SCS-MP2) method (Grimme, J. Chem Phys 2003, 118, 9095). For both alpha and gamma, the SCS-MP2 method improves over the MP2 results in comparison with reference values evaluated at the CCSD(T) level. Differences from the reference are in the range of 4-6% for alpha and 1-4% for gamma. In the case of gamma, the SCS-MP2 scheme improves not only over MP2 but also MP4 and CCSD. Further studies are needed on pi-conjugated systems to evaluate the generality of these results. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 3103-3111, 2009