Extending Linear Response: Inferences from Electron-Ion Structure Factors

TL;DR

This paper explores the extension of linear response theory to electron-ion structures in metallic fluids, demonstrating its accuracy and linking atomic and electronic scales for better understanding of experimental data.

Contribution

It introduces an approach combining linear response for electrons with hard-sphere models for ions to interpret electron-ion structure factors.

Findings

Linear response accurately predicts electron-ion structures in metals.

Neglecting higher response terms is justified due to atomic-electronic scale interference.

Electron-ion structure can be modeled using linear response plus ionic correlations.

Abstract

Linear response methods applied to electron systems often display a level of accuracy which is notable when viewed in terms of the strengths of perturbing interactions. Neglect of higher response terms is in fact justifiable in many cases and it can be shown to stem from an intrinsic interference between atomic and electronic length scales. For fluid metallic systems it can be further shown that electron-ion structure (increasingly accessible experimentally) can be understood from an application of linear response in the electron system, combined with hard-sphere like correlation for the ionic component.