Exchange and correlation in finite-temperature TDDFT★
Dept. of Physics, BOX 351560, Univ. of Washington,
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Received in final form: 11 May 2018
Published online: 4 July 2018
We discuss the finite-temperature generalization of time-dependent density functional theory (TDDFT). The theory is directly analogous to that at temperature T = 0. For example, the finite-T TDDFT exchange-correlation kernel fxc(T, n) in the local density approximation can again be expressed as a density derivative of the exchange correlation potential fxc(T, n) = [∂vxc(T, n)∕∂n]δ(r − r′), where n = N∕V is the electron number density. An approximation for the kernel fxc(T, n) is obtained from the finite-T generalization of the retarded cumulant expansion applied to the homogeneous electron gas. Results for fxc and the loss function are presented for a wide range of temperatures and densities including the warm dense matter regime, where T ≈ TF, the electron degeneracy temperature. The theory also permits a physical interpretation of the exchange and correlation contributions to the theory.
© EDP Sciences / Società Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2018