The macroscopic dielectric function of crystalline silicon is calculated within density-functional theory, considering exchange and correlation effects beyond the local-density approximation. Reproposing an original idea of Hohenberg and Kohn, we consider a functional based on the exchange and correlation kernel of the homogeneous electron gas, K(xc)(HEG). The same kernel is used in:the evaluation of the dielectric matrix, keeping local-held effects into account. The results, compared with those obtained in the local-density approximation, show a limited reduction of the well-known overestimation of the macroscopic dielectric constant. Results obtained for optical and energy loss spectra are also presented. [S0163-1829(99)00344-6].
Exchange and correlation effects beyond the LDA on the dielectric function of silicon / V. Olevano, M. Palummo, G. Onida, R. Del Sole. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 60:20(1999), pp. 14224-14233.
Exchange and correlation effects beyond the LDA on the dielectric function of silicon
G. OnidaPenultimo
;
1999
Abstract
The macroscopic dielectric function of crystalline silicon is calculated within density-functional theory, considering exchange and correlation effects beyond the local-density approximation. Reproposing an original idea of Hohenberg and Kohn, we consider a functional based on the exchange and correlation kernel of the homogeneous electron gas, K(xc)(HEG). The same kernel is used in:the evaluation of the dielectric matrix, keeping local-held effects into account. The results, compared with those obtained in the local-density approximation, show a limited reduction of the well-known overestimation of the macroscopic dielectric constant. Results obtained for optical and energy loss spectra are also presented. [S0163-1829(99)00344-6].Pubblicazioni consigliate
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