Screening of a point charge: a fixed-node diffusion Monte Carlo study

Erik Koch; Olle Gunnarsson; Richard M. Martin

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arXiv · cond-mat/9904257

Screening of a point charge: a fixed-node diffusion Monte Carlo study

Erik Koch·Olle Gunnarsson·Richard M. Martin

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Abstract

We study the static screening in a Hubbard-like model using fixed-node diffusion Monte Carlo. We find that the random phase approximation is surprisingly accurate even for metallic systems close to the Mott transition. As a specific application we discuss the implications of the efficient screening for the superconductivity in the doped Fullerenes. In the Monte Carlo calculations we use trial functions with two Gutzwiller-type parameters. To deal with such trial functions, we introduce a method for efficiently optimizing the Gutzwiller parameters, both in variational and in fixed-node diffusion Monte Carlo.

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Erik Koch, Olle Gunnarsson, Richard M. Martin. 1999-04-19. Screening of a point charge: a fixed-node diffusion Monte Carlo study. https://arxiv.org/abs/cond-mat/9904257

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