Spectral functions of the uniform electron gas via coupled-cluster theory and comparison to the GW and related approximations
We use ab initio coupled-cluster theory to compute the spectral function of the uniform electron gas at a Wigner-Seitz radius of r_s=4. The coupled-cluster approximations we employ go significantly beyond the diagrammatic content of state-of-the-art GW theory. We compare our calculations extensively to GW and GW-plus-cumulant theory, illustrating the strengths and weaknesses of these methods in capturing the quasiparticle and satellite features of the electron gas. Our accurate calculations further allow us to address the long-standing debate over the occupied bandwidth of metallic sodium. Our findings indicate that the future application of coupled-cluster theory to condensed phase material spectra is highly promising.
© 2016 American Physical Society. Received 14 December 2015. Revised 29 May 2016. CCSD calculations were carried out using a modified version of the ACES III code  through the University of Florida High Performance Computing Center. CCSDT calculations were performed using a modified version of the CFOUR code . Dynamical density-matrix renormalization-group calculations were done with the BLOCK code [63–65]. J.L. acknowledges support from Engineering and Physical Sciences Research Council under Grant No. EP/N005244/1 and also from the Thomas Young Centre under Grant No. TYC-101. S.G.L. and J.L. acknowledge support by the SciDAC Program on Excited State Phenomena in Energy Materials funded by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences and of Advanced Scientific Computing Research, under Contract No. DE-AC02-05CH11231 at Lawrence Berkeley National Laboratory (algorithm and code development) and by the NSF under Grant No. DMR15-1508412 (basic theory and formalism). D.A.M. is supported at the University of Texas by the National Science Foundation (Grant No. ACI-1148125). E.R. acknowledges the Computational Laboratory for Hybrid/Organic Photovoltaics of CNR-ISTM for a fellowship funded by the CNR-EFOR project. T.C.B. is supported by the Princeton Center for Theoretical Science. J.M., T.W., E.R., and G.K.-L.C. acknowledge primary support from DOE (SciDAC): Predictive Computing for Condensed Matter under Contract No. DE-SC0008624, and additional funding from DOE: Quantum Embedding for Correlated Electronic Structure in Large Systems and the Condensed Phase under Contract No. DE-SC0010530. G.K.-L.C. also acknowledges support from the Simons Foundation through the Simons Collaboration on the Many Electron Problem.
Accepted Version - 1512.04556.pdf
Published - PhysRevB.93.235139.pdf