Regensburg 2013 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 9: Focus Session: Frontiers of electronic structure theory I (O, jointly with HL, TT)
HL 9.6: Vortrag
Montag, 11. März 2013, 12:00–12:15, H36
RPA Correlation Potential in the Adiabatic Connection Fluctuation-Dissipation formalism — •Stefano de Gironcoli1, Nicola Colonna1, and Ngoc Linh Nguyen1,2 — 1Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, I-34136 Trieste, Italy — 2Theory and Simulation of Materials, École Polytechnique Fédérale de Lausanne (CH)
Calculations of correlation energies within the formally exact Adiabatic
Connection Fluctuation-Dissipation (ACFD) formalism, within the
Random Phase Approximation (RPA) for the exchange-correlation kernel,
have been recently carried out for a number of isolated and condensed
systems. The efficiency of such calculations has been greatly improved by
exploiting iterative algorithms to diagonalize RPA dielectric matrices
[1]. However for several systems correlation energies may significantly
depend about the choice of input single particle wavefunctions [2]. We derive
an expression for the RPA
self-consistent potential based on Density Functional Perturbation theory
and we present self-consistent RPA calculations for weakly bound molecular
dimers, including the controversial case of Beryllium dimer. In this case
the self-consistent determination of RPA potential is
crucial to determine the stability of the system which however results to
be unstable toward dissociation in separated fragments.
[1] H.-V. Nguyen and S. de Gironcoli, Phys. Rev. B 79, 205114 (2009); H. F. Wilson, F. Gygi, and G. Galli, Phys. Rev. B 78, 113303 (2008).
[2] Huy-Viet Nguyen and G.Galli, J. Chem.Phys. 132, 044109 (2010).