Exact exchange-correlation kernels for optical spectra of model systems

Article

关键词: DENSITY-FUNCTIONAL THEORY;    EXCITATION-ENERGIES;   

DOI  :  10.1103/PhysRevB.99.161102

来源: SCIE

【 摘 要 】

For two prototype systems, we calculate the exact exchange-correlation kernels f(xc)(x, x', omega) of time-dependent density functional theory. f(xc), the key quantity for optical absorption spectra of electronic systems, is normally subject to uncontrolled approximation. We find that, up to the first excitation energy, the exact f(xc) has weak frequency dependence and a simple, though nonlocal, spatial form. For higher excitations, the spatial behavior and frequency dependence become more complex. The accuracy of the underlying exchange-correlation potential is of crucial importance.

【 授权许可】

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