AI Article Synopsis
- The GFCCSD method is a powerful technique for accurately determining electronic band structures and total energies in various systems, outperforming many other theoretical methods.
- Calculations of single-electron energy spectra for systems like the one-dimensional LiH, C, and Be chains show that the bandgap narrows due to correlation effects, and GFCCSD can capture both quasiparticle and satellite peaks in the band structures.
- The study demonstrates that by limiting the active space in calculations, significant computational savings can be achieved while still producing results that align closely with full-band calculations.
Article Abstract
We demonstrate that the coupled-cluster singles-and-doubles Green's function (GFCCSD) method is a powerful and prominent tool drawing the electronic band structures and the total energies, which many theoretical techniques struggle to reproduce. We have calculated single-electron energy spectra via the GFCCSD method for various kinds of systems, ranging from ionic to covalent and van der Waals, for the first time: the one-dimensional LiH chain, one-dimensional C chain, and one-dimensional Be chain. We have found that the bandgap becomes narrower than in HF due to the correlation effect. We also show that the band structures obtained from the GFCCSD method include both quasiparticle and satellite peaks successfully. Besides, taking one-dimensional LiH as an example, we discuss the validity of restricting the active space to suppress the computational cost of the GFCCSD method. We show that the calculated results without bands that do not contribute to the chemical bonds are in good agreement with full-band calculations. With the GFCCSD method, we can calculate the total energies and spectral functions for periodic systems in an explicitly correlated manner.
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Article Synopsis
- The GFCCSD method is a powerful technique for accurately determining electronic band structures and total energies in various systems, outperforming many other theoretical methods.
- Calculations of single-electron energy spectra for systems like the one-dimensional LiH, C, and Be chains show that the bandgap narrows due to correlation effects, and GFCCSD can capture both quasiparticle and satellite peaks in the band structures.
- The study demonstrates that by limiting the active space in calculations, significant computational savings can be achieved while still producing results that align closely with full-band calculations.
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April 2016
Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
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