For some materials like noble metals, electron energy loss spectra have a complex structure that makes them difficult to analyze without the help of ab initio calculations. Various theoretical approaches can be used for this purpose, among which the time-dependent density functional perturbation theory (TDDFPT) which has been widely used to study plasmons in a number of bulk and surface systems. In the present paper we present a comparison of the results and performance of two different numerical implementations of TDDFPT: the Sternheimer and Liouville-Lanczos methods. The former approach is implemented in the thermo-pw module and the latter one in the turboEELS code of the QUANTUM ESPRESSO package for electronic structure calculations. In the present paper a comparison is made for bulk bismuth, a semimetal, taking into account spin-orbit coupling, as well as for bulk gold, a noble metal. We show that for these two examples, both codes gives identical results and the turboEELS code has a better performance than the thermo-pw code, and point out in which cases the usage of thermo-pw alone or of both codes can be advantageous.
Simulation of electron energy loss spectra with the turboEELS and thermo-pw codes / Motornyi, Oleksandr; Raynaud, Michèle; Dal Corso, Andrea; Vast, Nathalie. - In: JOURNAL OF PHYSICS. CONFERENCE SERIES. - ISSN 1742-6588. - 1136:1(2018), pp. 1-8. (Intervento presentato al convegno 29th IUPAP Conference on Computational Physics, CCP 2017 tenutosi a Universite Pierre et Marie Curie, Campus Jussieu, Paris, fra nel 2017) [10.1088/1742-6596/1136/1/012008].
Simulation of electron energy loss spectra with the turboEELS and thermo-pw codes
Dal Corso, Andrea;
2018-01-01
Abstract
For some materials like noble metals, electron energy loss spectra have a complex structure that makes them difficult to analyze without the help of ab initio calculations. Various theoretical approaches can be used for this purpose, among which the time-dependent density functional perturbation theory (TDDFPT) which has been widely used to study plasmons in a number of bulk and surface systems. In the present paper we present a comparison of the results and performance of two different numerical implementations of TDDFPT: the Sternheimer and Liouville-Lanczos methods. The former approach is implemented in the thermo-pw module and the latter one in the turboEELS code of the QUANTUM ESPRESSO package for electronic structure calculations. In the present paper a comparison is made for bulk bismuth, a semimetal, taking into account spin-orbit coupling, as well as for bulk gold, a noble metal. We show that for these two examples, both codes gives identical results and the turboEELS code has a better performance than the thermo-pw code, and point out in which cases the usage of thermo-pw alone or of both codes can be advantageous.File | Dimensione | Formato | |
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