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arXiv · 1801.09977

Comparing many-body approaches against the helium atom exact solution

Jing Li·N. D. Drummond·Peter Schuck·Valerio Olevano
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Abstract

Over time, many different theories and approaches have been developed to tackle the many-body problem in quantum chemistry, condensed-matter physics, and nuclear physics. Here we use the helium atom, a real system rather than a model, and we use the exact solution of its Schrödinger equation as a benchmark for comparison between methods. We present new results beyond the random-phase approximation (RPA) from a renormalized RPA (r-RPA) in the framework of the self-consistent RPA (SCRPA) originally developed in nuclear physics, and compare them with various other approaches like configuration interaction (CI), quantum Monte Carlo (QMC), time-dependent density-functional theory (TDDFT), and the Bethe-Salpeter equation on top of the GW approximation. Most of the calculations are consistently done on the same footing, e.g. using the same basis set, in an effort for a most faithful comparison between methods.

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Jing Li, N. D. Drummond, Peter Schuck, Valerio Olevano. 2019-03-01. Comparing many-body approaches against the helium atom exact solution. https://doi.org/10.21468/scipostphys.6.4.040

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