Thursday, 26 July 2001,  11:00 am 

Le Couteur Building Seminar Room

Dr Robert J. Bursill

School of Physics
University of NSW, Sydney

Semi-empirical Theories of Excited States in Conjugated Polymers

ABSTRACT:

Semi-empirical approaches such as the Pariser-Parr-Pople model have the potential to describe quite precisely a wide range of excited state properties (linear and two-photon absorption, nonlinear optical states, excited state geometries and soliton structures) in pi-conjugated systems such as conjugated oligomers and polymers, graphite sheets, nanotubes and fullerenes. However, it is only in recent times that, through the advent of the density matrix renormalisation group (DMRG), we have had access to the predictions of semi-empirical theories. Here we review what has been achieved to date and what we hope to achieve in the future, through the application of DMRG to these models.