Showing papers by "Sergei Tretiak published in 1996"
TL;DR: In this paper, the nonlinear optical polarizabilities of conjugated molecules are calculated and analyzed using a few collective electronic normal modes, and a firm relationship between the optical response and ground state charge distributions and bonding network is established.
77 citations
TL;DR: In this paper, an iterative algorithm is developed for calculating nonlinear optical polarizabilities using a series of generalized sum rules that resemble the Lanczos algorithm and connect spectral moments of the driven single-electron density matrix to ground state charge distributions and bonding network.
Abstract: An iterative algorithm is developed for calculating nonlinear optical polarizabilities using a series of generalized sum rules that resemble the Lanczos algorithm and connect spectral moments of the driven single‐electron density matrix to ground state charge distributions and bonding network. The size scaling and saturation of off‐resonant polarizabilities (up to seventh order) of polyacetylene oligomers with up to 300 carbon atoms is analyzed in terms of collective electronic oscillators. Simple analytical expressions for size and bond‐length alternation dependence of off‐resonant polarizabilities are derived using a single‐oscillator approximation.
71 citations
TL;DR: Using sum rules for spectral moments of linear and nonlinear absorption, it is shown that the jth order off-resonant polarizabilities of polyacetylene chains scale as ,jD2jNj11ysN 1 Ldj ; N is the number of carbon atoms, D the bond-length alternation, and LsDd the exciton coherence size.
Abstract: Using sum rules for spectral moments of linear and nonlinear absorption we show that the jth order off-resonant polarizabilities of polyacetylene chains scale as $\ensuremath{\sim}j{\ensuremath{\Delta}}^{\ensuremath{-}j}{N}^{j+1}/(N+L{)}^{j}$; $N$ is the number of carbon atoms, $\ensuremath{\Delta}$ the bond-length alternation, and $L(\ensuremath{\Delta})$ the exciton coherence size. This result is in excellent agreement with time-dependent Hartree-Fock calculations performed for chains with up to 200 carbon atoms.
60 citations