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All instances / t-J

t-J square 8x8, J = 0.4, 8 holes

Best values (rules §6)

best variational -0.64266(8) VMC (Gutzwiller)
10.1103/PhysRevLett.88.117002, · the lowest unflagged variational energy, a strict variational bound
best projected -0.66672(6) FN-GFMC (Gutzwiller)
10.1103/PhysRevLett.88.117002, · the lowest unflagged projected energy, a projected estimate, which depends on its node or constraint
best extrapolated -0.671(1) VMC (Gutzwiller)
10.1103/PhysRevLett.88.117002, · the lowest unflagged extrapolated energy, an extrapolation, not a bound

Energies as E/site. Classes are different claims and are not ranked against each other.

The Hamiltonian

H = −t ∑⟨ij⟩,σ P(c†iσcjσ + h.c.)P + J ∑⟨ij⟩ (Si·Sj − ninj/4)

t-J model: P projects out doubly occupied sites, S = σ/2. t = 1, J = 0.4; the exchange term includes −ninj/4. N↑ = 28, N↓ = 28 on 64 sites (8 holes). Cluster: 8 x 8 torus (arXiv:cond-mat/0110460: '8 holes on the 8 x 8 lattice', PBC clusters).

lattice
square
sites
64
boundary
periodic
t
1
J
0.4
N_up
28
N_dn
28
nn_term
true
energies
3

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. The exact energy comes first where there is one; in every other group the lowest unflagged energy is its best value, and each row's distance is to that best (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 class bestσVar(E)V-score methodsourcecodeyearcomment
-0.64266best variational 0 8.0e-5 n/a n/a VMC (Gutzwiller)
peer reviewed
10.1103/PhysRevLett.88.117002, 2002

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 class bestσVar(E)V-score methodsourcecodeyearcomment
-0.66672best projected 0 6.0e-5 n/a n/a FN-GFMC (Gutzwiller)
peer reviewed
10.1103/PhysRevLett.88.117002, 2002

Extrapolations (1)

Zero-variance or bond-dimension extrapolations. These are not bounds: no ansatz reached the number.

E/sitedistance to class bestσVar(E)V-score methodsourcecodeyearcomment
-0.671best extrapolated 0 1.0e-3 n/a n/a VMC (Gutzwiller)
peer reviewed
10.1103/PhysRevLett.88.117002, 2002

How these numbers were read

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

-0.671(1), VMC (Gutzwiller)

Checked 2026-10-22 · source text of arXiv:cond-mat/0110460 read locally (arXiv HTML or pypdf layout text); value copied from the harvested cell and the text, no LLM transcription of numbers; first reading and an adversarial second reading (2026-10-22)

Reported as. −0.671(1)

text: 8 holes on the 8 x 8 lattice, J/t = 0.4, energy per site (the zero variance extrapolation) (line 156); version read: arXiv text (sources/cond-mat-0110460.txt); the journal version was not reached from this session (the publisher returned 403), to be read on the verification pass (RULES.md 8) | Eq. (1): H = J sum (S_i.S_j - n_i n_j / 4) - t sum c~+c~ + h.c.; energies per site in units of t ('best variational energy per site', 'E = ... t'), 8 holes on the 8 x 8 PBC cluster, J/t = 0.4.

-0.66672(6), FN-GFMC (Gutzwiller)

Checked 2026-10-22 · source text of arXiv:cond-mat/0110460 read locally (arXiv HTML or pypdf layout text); value copied from the harvested cell and the text, no LLM transcription of numbers; first reading and an adversarial second reading (2026-10-22)

Reported as. −0.66672(6)

text: 8 holes on the 8 x 8 lattice, J/t = 0.4, energy per site (best variational energy per site (FN+2LS)) (line 154); version read: arXiv text (sources/cond-mat-0110460.txt); the journal version was not reached from this session (the publisher returned 403), to be read on the verification pass (RULES.md 8) | Eq. (1): H = J sum (S_i.S_j - n_i n_j / 4) - t sum c~+c~ + h.c.; energies per site in units of t ('best variational energy per site', 'E = ... t'), 8 holes on the 8 x 8 PBC cluster, J/t = 0.4.

-0.64266(8), VMC (Gutzwiller)

Checked 2026-10-22 · source text of arXiv:cond-mat/0110460 read locally (arXiv HTML or pypdf layout text); value copied from the harvested cell and the text, no LLM transcription of numbers; first reading and an adversarial second reading (2026-10-22)

Reported as. −0.64266(8)

text: 8 holes on the 8 x 8 lattice, J/t = 0.4, energy per site (the pure variational calculation) (line 157); version read: arXiv text (sources/cond-mat-0110460.txt); the journal version was not reached from this session (the publisher returned 403), to be read on the verification pass (RULES.md 8) | Eq. (1): H = J sum (S_i.S_j - n_i n_j / 4) - t sum c~+c~ + h.c.; energies per site in units of t ('best variational energy per site', 'E = ... t'), 8 holes on the 8 x 8 PBC cluster, J/t = 0.4.

Coverage

Newest published number here: 2002.

This instance as data

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