Discontinuity of the chemical potential in reduced-density-matrix-functional theory
We present a novel method for calculating the fundamental gap. To this end, reduced-density-matrix-functional theory is generalized to fractional particle number. For each fixed particle number, M, the total energy is minimized with respect to the natural orbitals and their occupation numbers. This...
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Published in | Europhysics letters Vol. 77; no. 6; pp. 67003 - 67003 (6) |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
IOP Publishing
01.03.2007
EDP Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | We present a novel method for calculating the fundamental gap. To this end, reduced-density-matrix-functional theory is generalized to fractional particle number. For each fixed particle number, M, the total energy is minimized with respect to the natural orbitals and their occupation numbers. This leads to a function, $E_{{\rm tot}}^{M}$, whose derivative with respect to the particle number has a discontinuity identical to the gap. In contrast to density functional theory, the energy minimum is generally not a stationary point of the total-energy functional. Numerical results, presented for alkali atoms, the LiH molecule, the periodic one-dimensional LiH chain, and solid Ne, are in excellent agreement with CI calculations and/or experimental data. |
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Bibliography: | istex:DE6A9F2BF4CCE6A39A7003010E6421CF543441FC ark:/67375/80W-DF1TBRRH-D publisher-ID:epl10164 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0295-5075 1286-4854 |
DOI: | 10.1209/0295-5075/77/67003 |