title: On the accurate calculation of polarizabilities and second hyperpolarizabilities of polyacetylene oligomer chains using the CAM-B3LYP density functional.
abstract: The polarizability and second hyperpolarizability of polyacetylene oligomer chains of increasing size up to C(24)H(26) were investigated by means of the Coulomb-attenuating method (CAM-B3LYP) using response theory. It was found that this long-range corrected density functional removes to large parts the overestimation observed for standard methods and in many cases provides results close to those of coupled cluster calculations. A direct comparison to experimentally observed dynamic hyperpolarizabilities is made to estimate the accuracy of the method. A basis set study revealed a noticeable contribution of diffuse orbitals to the hyperpolarizability also for larger oligomers. Furthermore, CAM-B3LYP is also confirmed to provide molecular geometries close to experimentally observed structures, especially for longer chain lengths.
authors.affiliation: Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, Wolfgang-Pauli-Str. 10, 8093 Zürich, Switzerland.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Limacher
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Mikkelsen
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Lüthi