Dresden 2017 – wissenschaftliches Programm
MM 35: Electronic Structure Theory: New Concepts and Developments in Density Functional Theory and Beyond
MM 35.11: Poster
Dienstag, 21. März 2017, 18:30–20:30, P2-OG4
A Hubbard U based correction method for exciton binding in neutral excitations: TDDFT+U — •Okan K. Orhan and David D. O’Regan — School of Physics, Trinity College Dublin, Ireland.
The DFT+U (density-functional theory + Hubbard U) method is widely used to improve the approximate DFT description of the ground state properties of solids and molecules comprising transition-metal ions. We introduce its generalisation to the time domain in the guise of TDDFT+U (time-dependent DFT+U), intended to extend these improvements to the calculation of neutral excitations. Related methods have been previously discussed [1,2], and here we offer a detailed treatment emphasising single-particle excitations and absorption spectra. Our software implementation is a combination of the linear-scaling DFT+U  and linear-response TDDFT  functionalities available in the ONETEP code . In a study of small nickel-comprising molecules, we find that the Hubbard U correction to the exchange-correlation kernel acts to partially cancel the effects of the DFT+U term of the underlying ground-state potential, enhancing the exciton binding.
 C.-C. Lee, H. C. Hsueh, and W. Ku, Phys. Rev. B 82, 081106(R) (2010).  D. Shin, G. Lee, Y. Miyamoto, and N. Park, J. Chem. Theory Comput., 12 (1), pp 201-208 (2016).  D. D. O’Regan, N. D. M. Hine, M. C. Payne, and A. A. Mostofi, Phys. Rev. B 85, 085107 (2012).  T. J. Zuehlsdorff, N. D. M. Hine, M. C. Payne, and P. D. Haynes, J. Chem. Phys. 143, 204107 (2015).  C. K. Skylaris, P. D. Haynes, A. A. Mostofi, and M. C. Payne, J. Chem. Phys., 122 (8), 084119 (2005). For the ONETEP code, see http://www.onetep.org