Abstract
A new method for calculating optical absorption spectra within linear-scaling density functional theory (LS-DFT) is presented, incorporating a scheme for optimizing a set of localized orbitals to accurately represent unoccupied Kohn-Sham states. Three different schemes are compared and the most promising of these, based on the use of a projection operator, has been implemented in a fully functional LS-DFT code. The method has been applied to the calculation of optical absorption spectra for the metal-free phthalocyanine molecule and the conjugated polymer poly(para-phenylene). Excellent agreement with results from a traditional DFT code is obtained.
3 More- Received 18 August 2011
DOI:https://doi.org/10.1103/PhysRevB.84.165131
©2011 American Physical Society