The exact universal exchange-only local field factor of the uniform electron gas and its near-cancellation by parallel-spin correlation near 2kF
Year: 2026
Type: preprint
Abstract: Python code accompanying C. A. Kukkonen, "The exact universal exchange-only local field factor of the uniform electron gas and its near-cancellation by parallel-spin correlation near 2kF," arXiv:2607.20403.Contents:ev_gx.py — The sole numerical authority for the paper. Evaluates the exact static exchange-only local field factor Gx(q,0), Eq. (6) of the paper, from the Engel-Vosko first-order polarizability [Phys. Rev. B 42, 4940 (1990)], Appendix A. Functions Gx_exact(q/kF), I_EV(Q), and L_lind(Q), with Q = q/2kF. Verified against every analytic check of that reference, including I(0) = -1 and I(1) = -pi^2/24 to machine precision, Gx(2kF) = pi^2/6, and Gx(q -> inf) = 1/3.make_figs_1_3_5.py — Figures 1, 3, and 5, and the density-wave threshold curves of Eq. (11), reproducing the SDW minimum at rs = 4.96 and the CDW minimum at rs = 10.62.make_fig2.py — Figure 2. The Tripathy-Mandal 1977 and BDL 1980 values are transcribed in the script from the published Tables I of Phys. Rev. B 16, 231 (1977) and Phys. Rev. B 21, 1363 (1980).make_fig4.py — Figure 4, the quantum Monte Carlo data points and the spin-resolved subtraction.README.md — File descriptions and data notes.Third-party numerical data are not redistributed here: the VDMC G+ and G- points were supplied by K. Chen and the McLVP kernel grids by V. U. Nazarov (see the paper's Data Availability statement). The scripts that use them are included; the data are available from their original authors. The Kaplan-Kukkonen local field factors install with pip install AKCK_LFF.Requirements: Python 3 with numpy, scipy, matplotlib, openpyxl, and AKCK_LFF. Run: python3 ev_gx.py for the self-test.Version 2: quadrature tolerances tightened so the large-q integrands are fully resolved; figure scripts updated to the current version of the paper. Results below 3kF are unchanged.
Source: arXiv (Cornell University)
Author: Kukkonen, Carl A.
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7208709294