TY - JOUR
KW - paper
KW - TDDFT
AU - Francesco Sottile
AU - Olevano V
AU - Lucia Reining
AB - We have established and implemented a fully ab initio method which allows one to calculate optical absorption spectra, including excitonic effects, without solving the cumbersome Bethe-Salpeter equation, but obtaining results of the same precision. This breakthrough has been achieved in the framework of time-dependent density-functional theory, using new exchange-correlation kernels f(xc) that are free of any empirical parameter. We show that the same excitonic effects in the optical spectra can be reproduced through different f(xc)\textquoterights, ranging from frequency-dependent ones to a static one, by varying the kernel\textquoterights spatial degrees of freedom. This indicates that the key quantity is not f(xc), but f(xc) combined with a response function. We present results for the optical absorption of bulk Si and SiC in good agreement with experiment, almost indistinguishable from those of the Bethe-Salpeter approach.
BT - Phys. Rev. Lett.
CY - ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
DA - AUG 1
DO - 10.1103/PhysRevLett.91.056402
M1 - 5
N2 - We have established and implemented a fully ab initio method which allows one to calculate optical absorption spectra, including excitonic effects, without solving the cumbersome Bethe-Salpeter equation, but obtaining results of the same precision. This breakthrough has been achieved in the framework of time-dependent density-functional theory, using new exchange-correlation kernels f(xc) that are free of any empirical parameter. We show that the same excitonic effects in the optical spectra can be reproduced through different f(xc)\textquoterights, ranging from frequency-dependent ones to a static one, by varying the kernel\textquoterights spatial degrees of freedom. This indicates that the key quantity is not f(xc), but f(xc) combined with a response function. We present results for the optical absorption of bulk Si and SiC in good agreement with experiment, almost indistinguishable from those of the Bethe-Salpeter approach.
PB - AMERICAN PHYSICAL SOC
PP - ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
PY - 2003
EP - 056402
T2 - Phys. Rev. Lett.
TI - Parameter-free calculation of response functions in time-dependent density-functional theory
UR - http://dx.doi.org/10.1103/PhysRevLett.91.056402
VL - 91
ER -