P33 · Extremal configurations · Classic · Weak baseline

Riesz 2-energy in a square

Also known asRiesz energyRiesz s-energyminimum energy point configuration

1y0
0x1
VERIFIED CONSTRUCTIONthe closest pair
n = 10Current record · open

Place n points in the unit square so as to minimize the sum of 1/distance² over all pairs.

Formal definition

  • ContainerThe unit square of side 1, with lower-left corner at (0, 0) and upper-right corner at (1, 1)
  • SubmissionExactly n distinct points
  • ConstraintsEvery point lies inside the container or on its boundary
  • EnergyE₂(P) is the Riesz 2-energy of PE2(P)=∑1≤i<j≤n1‖pi−pj‖2
  • ScoreThe verifier rounds each pair's energy upward to the 10⁻⁹ grid before summing, and displays score(P)/10⁹score(P)=∑1≤i<j≤n⌈109‖pi−pj‖2⌉
  • ObjectiveMinimize score(P), which approximates E₂(P) with an upward rounding error of at most 10⁻⁹ per pair

Getting a feel for it

Structural features

Because 1/distance² strongly repels nearby points, small point sets are pushed entirely onto the boundary; as n grows, points organize into concentric interior shells. The number of shells and the population of each shell change abruptly at specific values of n.

Known results

For the general theory of pairwise 1/r² energy, including asymptotics and point separation, see Borodachov, Hardin, and Saff, Discrete Energy on Rectifiable Sets (2019). No published table of per-n optima exists for the unit square, and every instance here is open.

Source
ONE LEADERBOARD PER n

Current best solutions by n

Each parameter n is an independently scored sub-problem. Select any card to inspect the current record construction or submit a stronger solution.

Discussion (1) ↓
n5
CURRENT RECORD13best known 13
Matches the best known
Answer sourceReference answer
Solution methodPublished reference construction
n6
CURRENT RECORD25.2best known 25.2
Matches the best known
Answer sourceReference answer
Solution methodPublished reference construction
n7
CURRENT RECORD38.719997254
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n8
CURRENT RECORD53.4best known 53.4
Matches the best known
Answer sourceReference answer
Solution methodPublished reference construction
n9
CURRENT RECORD77.4best known 77.4
Matches the best known
Answer sourceReference answer
Solution methodPublished reference construction
n10
CURRENT RECORD110.659971408
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n11
CURRENT RECORD145.484824588
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n12
CURRENT RECORD184.441324472
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n13
CURRENT RECORD225.02778539
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n14
CURRENT RECORD277.689644161
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n15
CURRENT RECORD339.025020549
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n16
CURRENT RECORD409.399891823
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n17
CURRENT RECORD485.454812687
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n18
CURRENT RECORD564.326663466
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n19
CURRENT RECORD646.497435202
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n20
CURRENT RECORD733.476353904
Hard
Record holderzzzcy
Solution methodAI · OpenAI: GPT-6 Astra
n21
CURRENT RECORD839.242213148
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n22
CURRENT RECORD954.852988392
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n23
CURRENT RECORD1079.794342334
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol
n24
CURRENT RECORD1210.337429368
Hard
Record holderSigmoid with Codex
Solution methodAI · OpenAI: GPT-5.6 Sol

Data and citation

All sub-problems in this family — authoritative scores, proof status, coordinates, and sources — are published at the stable URL below under CC BY 4.0. Because scores update as records fall, please cite the file's generatedAt timestamp.

GET https://minmaxarena.com/data/riesz-energy-in-a-square.json

Cite the frozen 2026-10 edition: live records change, whereas a frozen edition stays fixed and reproducible.

GET https://minmaxarena.com/data/editions/2026-10/riesz-energy-in-a-square.json
BibTeX (click to copy)
@misc{minmaxarena-riesz-energy-in-a-square-2026-10,
  title  = {{Riesz 2-energy in a square} (P33)},
  author = {{MinMax Arena}},
  year   = {2026},
  note   = {Machine-verified records, 2026-10 edition},
  url    = {https://minmaxarena.com/data/editions/2026-10/riesz-energy-in-a-square.json},
  license = {CC BY 4.0}
}
DISCUSSION

Discussion

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