Ab-initio nonlinear optical properties of finite polyacetylene oligomers

Summary form only given. A comprehensive ab initio quantum chemistry study of the nonlinear optical properties of polyacetylene has been carried out using the finite oligomer method. The various aspects taken into account include: (1) behavior of properties with increasing chain length in the very long chain limit; (2) electron correlation; (3) distortion due to the coupling of vibrations with field-induced electronic polarization; and (4) non-resonant frequency dispersion. Our results are compared with experiment and a simple classical model for the induced polarization is presented.