Dynamical linear response of TDDFT withLDA+Ufunctional: Strongly hybridized Frenkel excitons in NiO

Chi-Cheng Lee, H. C. Hsueh, Wei Ku
2010 Physical Review B  
Within the framework of time-dependent density-functional theory (TDDFT), we derive the dynamical linear response of LDA+U functional and benchmark it on NiO, a prototypical Mott insulator. Formulated using real-space Wannier functions, our computationally inexpensive framework gives detailed insights into the formation of tightly bound Frenkel excitons with reasonable accuracy. Specifically, a strong hybridization of multiple excitons is found to significantly modify the exciton properties.
more » ... iton properties. Furthermore, our study exposes a significant generic limitation of adiabatic approximation in TDDFT with hybrid functionals and in existing Bethe-Salpeter-equation approaches, advocating the necessity of strongly energy-dependent kernels in future development.
doi:10.1103/physrevb.82.081106 fatcat:ueatnf3utvfxbh35spun7tj64e