Dresden 2014 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 66: Focus Session: Frontiers of Electronic Structure Theory - Non-Equilibrium Phenomena at the Nano-Scale IV (organized by O)

TT 66.8: Talk

Wednesday, April 2, 2014, 12:30–12:45, TRE Ma

What Koopmans’ compliant orbital-density dependent functionals can do for you: a comprehensive benchmark of the G2-set — •Giovanni Borghi¹, Ngoc Linh Nguyen¹, Andrea Ferretti², Ismaila Dabo³, and Nicola Marzari¹ — ¹École Polytechnique Fédérale de Lausanne, Lausanne (VD), CH — ²Centro S3, CNR–NANO, Modena, IT — ³Department of Materials Science and Engineering, Penn State University, University Park (PA), USA

In this talk we present the results of benchmark calculations of the structure and electronic-structure of all molecules in the g2 set, using different flavours for Koopmans’ compliant (KC) functionals. Results are compared not only to LDA and PBE, but also to orbital-density dependent calculations with the Perdew-Zunger self-interaction correction.

Our results assess the accuracy of Koopmans’ compliant functionals in improving semilocal functionals to predict electronic eigenvalues and in particular ionization energies, with an accuracy that for molecules seems to be comparable or superior to that of many-body (GW) approaches. We also highlight how the Koopmans’ condition tends to preserve the potential energy surface of the underlying functional, with higher reliability than e.g. PBE in structural predictions, while also providing good estimates of atomization energies.

The talk will also provide a general introduction to the theory of Koopmans’ compliant functionals and their implementation in existing electronic structure codes.
Ref. Dabo et al., PRB 82, 115121 (2010), and Psik highlight (2012).