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arXiv · 1002.1101

Dynamical Linear Response of TDDFT with LDA+U Functional: strongly hybridized Frenkel excitons in NiO

Chi-Cheng Lee·H. C. Hsueh·Wei Ku
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Abstract

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. 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.

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Chi-Cheng Lee, H. C. Hsueh, Wei Ku. 2010-02-05. Dynamical Linear Response of TDDFT with LDA+U Functional: strongly hybridized Frenkel excitons in NiO. https://doi.org/10.1103/physrevb.82.081106

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