Coupled Cluster Greens function formulations based on the effective Hamiltonians
arXiv:1910.00394 · doi:10.1080/00268976.2020.1725669
Abstract
We demonstrate that the effective Hamiltonians obtained with the downfolding procedure based on double unitary coupled cluster (DUCC) ansatz can be used in the context of Greens function coupled cluster (GFCC) formalism to calculate spectral functions of molecular systems. This combined approach (DUCC-GFCC) provides a significant reduction of numerical effort and good agreement with the corresponding all-orbital GFCC methods in energy windows that are consistent with the choice of active space. These features are demonstrated on the example of two benchmark systems: H2O and N2, where DUCC-GFCC calculations were performed for active spaces of various sizes.
References in corpus (18)
- Quasiparticle Self-Consistent GW Theory
- Renormalization of Molecular Electronic Levels at Metal-Molecule Interfaces
- Truncated Configuration Interaction expansions as solvers for correlated quantum impurity models and dynamical mean field theory
- Dynamical mean-field theory from a quantum chemical perspective
- The description of strong correlation within self-consistent Green's function second-order perturbation theory
- Downfolding of many-body Hamiltonians using active-space models: extension of the sub-system embedding sub-algebras approach to unitary coupled cluster formalisms
- Towards ab initio self-energy embedding theory in quantum chemistry
- On The Relation Between Equation-of-Motion Coupled-Cluster Theory and the GW Approximation
- Spectral Functions of the Uniform Electron Gas via Coupled-Cluster Theory and Comparison to the and Related Approximations
- Generalized self-energy embedding theory
- Real time cumulant approach for charge transfer satellites in x-ray photoemission spectra
- Random-phase approximation excitation energies from approximate equation-of-motion ring coupled-cluster doubles
- Band structures in coupled-cluster singles-and-doubles Green's function (GFCCSD)
- Approximate Green's Function Coupled Cluster Method Employing Effective Dimension Reduction
- Explicitly correlated formalism for second-order single-particle Green's function
- Comparison of Green's functions for transition metal atoms using self-energy functional theory and coupled-cluster singles and doubles (CCSD)
- Green's function coupled cluster formulations utilizing extended inner excitations
- Quasiparticle energy spectra of isolated atoms from coupled-cluster singles and doubles (CCSD): Comparison with exact CI calculations