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All instances / Hubbard

Hubbard square 32x32, U = 8, n = 0.875

Record

-0.7548 E/site

Fixed-node GFMC (trial state: SCALE, 1 conv layer)

Gu et al. (2026) · lowest unflagged energy published, a projected estimate (rules §6)

The Hamiltonian

H = −t ∑⟨ij⟩,σ (c†iσcjσ + h.c.) + U ∑i ni↑ni↓

t = 1, U = 8, N↑ = N↓ = 448 on 1024 sites.

lattice
square
sites
1024
boundary
periodic
Nf
448
U
8
energies
2

Stored as a total energy; quoted here as E/site, which is what the papers report (how the conversion works).

Every published energy

Grouped by what the number is. On a solved instance the exact energy is the record; otherwise the lowest unflagged energy of any group holds it (rules §6).

Strict variational upper bounds (1)

Energies that a variational state reached (VMC, DMRG and MPS at finite bond dimension, PEPS, NQS, VQE). Each is an upper bound on the ground-state energy.

E/sitedistance to recordσVar(E)V-score methodsourceyear
-0.7501 4.7e-3 n/a n/a n/a SCALE (1 conv layer)
peer reviewed
Gu et al. (2026) 2026

Projected or fixed-node estimates (1)

Variational only within a constraint: fixed-node, constrained-path, GFMC on a trial state. Each depends on its node or constraint, so two of them are not cleanly comparable to each other or to strict bounds.

E/sitedistance to recordσVar(E)V-score methodsourceyear
-0.7548record 0 n/a n/a n/a Fixed-node GFMC (trial state: SCALE, 1 conv layer)
peer reviewed
Gu et al. (2026) 2026

How these numbers were read

Where each number below was read, and how it was checked.

-0.7548, Fixed-node GFMC (trial state: SCALE, 1 conv layer)

Checked 2026-10-22 · source text of arXiv:2604.25775 read locally (arXiv HTML or pypdf layout text); value copied from the harvested cell and the text, no LLM transcription of numbers; single reading

Reported as. −0.7548

Sec. III C.2 'Accuracy on large systems', last paragraph (32x32, t'=0, PBC per Fig. 7 caption); sources/2604.25775.txt line 505; version read: arXiv v1 (sources/2604.25775.txt); APS copy not reached (403, 2026-10-16) | Eq. (8): H = -t sum_<ij> - t' sum_<<ij>> + U sum n_up n_dn, t = 1, U = 8, doping 1/8 (Sec. III), periodic unless the column says OBC; energies per site. Pinning fields only in pre-training (App. C).

-0.7501, SCALE (1 conv layer)

Checked 2026-10-22 · source text of arXiv:2604.25775 read locally (arXiv HTML or pypdf layout text); value copied from the harvested cell and the text, no LLM transcription of numbers; single reading

Reported as. −0.7501

Sec. III C.2 'Accuracy on large systems', last paragraph (32x32, t'=0, PBC per Fig. 7 caption); sources/2604.25775.txt line 505; version read: arXiv v1 (sources/2604.25775.txt); APS copy not reached (403, 2026-10-16) | Eq. (8): H = -t sum_<ij> - t' sum_<<ij>> + U sum n_up n_dn, t = 1, U = 8, doping 1/8 (Sec. III), periodic unless the column says OBC; energies per site. Pinning fields only in pre-training (App. C).

Coverage

Newest published number here: 2026.

This instance as data

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