Coupled cluster Green function: Model involving single and double excitations
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A key aspect of this work is the determination of the frequency dependent self-energy, Σ(ω), which reveals a diagonally dominate block structure where as the non-local correlation increases, the block size increases proportionally.Abstract:
In this paper, we report on the development of a parallel implementation of the coupled-cluster (CC) Green function formulation (GFCC) employing single and double excitations in the cluster operator (GFCCSD). A key aspect of this work is the determination of the frequency dependent self-energy, Σ(ω). The detailed description of the underlying algorithm is provided, including approximations used that preserve the pole structure of the full GFCCSD method, thereby reducing the computational costs while maintaining an accurate character of methodology. Furthermore, for systems with strong local correlation, our formulation reveals a diagonally dominate block structure where as the non-local correlation increases, the block size increases proportionally. To demonstrate the accuracy of our approach, several examples including calculations of ionization potentials for benchmark systems are presented and compared against experiment.read more
Citations
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References
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Assessment of the single-root multireference Brillouin–Wigner coupled- cluster method: Test calculations on CH2, SiH2, and twisted ethylene
TL;DR: In this article, the single-root multireference Brillouin-Wigner coupled-cluster (MR BWCC) theory has been implemented in the ACES II program package at the CCSD level of approximation.
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Electron propagator theory: an approach to prediction and interpretation in quantum chemistry
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On the accuracy of ionization potentials calculated by Green’s functions
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GW quasiparticle spectra from occupied states only
TL;DR: In this article, a method for the calculation of quasi-particle spectra in the GW approximation, without any explicit reference to empty one-electron states, was proposed. But this method is not suitable for the analysis of large molecules such as free-base tetraphenylporphyrin.
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Second order many-body perturbation approximations to the Coupled Cluster Green's Function.
Marcel Nooijen,J.G. Snijders +1 more
TL;DR: In this paper, the authors investigated the accuracy that can be obtained if the CCSD coefficients are replaced by their MBPT(2) analogs and discussed some additional diagonal approximations that might prove especially useful in polymer calculations, and compared with traditional Green's function calculations based on a second order approximation to the irreducible self-energy.