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Structural and Electronic Instabilities in Polyacenes: Density Matrix Renormalization Group Study of a Long--Range Interacting Model

C. Raghu·Y. Anusooya Pati·S. Ramasesha
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Abstract

We have carried out Density Matrix Renormalization Group (DMRG) calculations on the ground state of long polyacene oligomers within a Pariser-Parr-Pople (PPP) Hamiltonian. The PPP model includes long-range electron correlations which are required for physically realistic modeling of conjugated polymers. We have obtained the ground state energy as a function of the dimerization $δ$ and various correlation functions and structure factors for $δ=0$. From energetics, we find that while the nature of the Peierls' instabilityin polyacene is conditional and strong electron correlations enhance the dimerization. The {\it cis} form of the distortion is favoured over the {\it trans} form. However, from the analysis of correlation functions and associated structure factors, we find that polyacene is not susceptible to the formation of a bond order wave (BOW), spin density wave (SDW) or a charge density wave (CDW) in the ground state.

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C. Raghu, Y. Anusooya Pati, S. Ramasesha. 2001-10-08. Structural and Electronic Instabilities in Polyacenes: Density Matrix Renormalization Group Study of a Long--Range Interacting Model. https://doi.org/10.1103/physrevb.65.155204

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