SpaceChem Bench: QT-2

quantum_2 Hard Quantum tunnels Single-reactor 63 Corvi · SpaceChem Bench report →

Inputs: α Chlorine (Cl2). Output: ω Chlorine (Cl2) ×10. Features: Bonders (2), Sensor, Quantum tunnels (2).

In SpaceChem Bench, 16 LLMs each had one attempt at this SpaceChem puzzle, with 60 minutes to build a working solution and keep optimizing it, without seeing the community archive. 13 of 16 models solved it. No model found a new Pareto-frontier point beyond the frozen community archive.

13 / 16models solved it
80best LLM cycles (80 community)
0new frontier points

Records

ScoreCommunity bestBest LLMModel
Cycles8080GPT-6 Astra Ties record
Reactors11DeepSeek V4.1 Flash Ties record
Symbols1111GPT-6 Astra Ties record

Community records from the community archive when we froze it on October 18, 2026. A point counts only after fresh-game replay and SChem’s precognition check.

Pareto frontier

Pareto explorer

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Community archiveModel frontier pointNew frontier point
Select a point with the mouse or keyboard to inspect its scores and reactor blueprint.

Search over time

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Every model

ModelSolvedBest cyclesBest reactorsBest symbolsNew frontier points
01GPT-6 AstraYes80111—
02Gemini 4 ArgonYes80112—
03Opus 5.5Yes81111—
04GPT-6.1 SolYes83111—
05Muse Wonder 1.0Yes85111—
06Sonnet 5.5Yes101117—
07Fable 5.1Yes102117—
08Kimi K3.1 ProYes104122—
09Gemini 3.8 FlashYes117119—
10Grok 4.7Yes161124—
11GPT-6 LunaYes224126—
12DeepSeek V4.1 FlashYes267133—
13Muse Spark 1.3Yes293130—
14GLM-5.3No————
15Haiku 5.5No————
16MiMo-V2.6-ProNo————

Best scores can come from different solutions. New frontier points are not matched or beaten on all three scores by any community solution.

Best model solutions

These solutions are in SpaceChem Community Edition export format and released under the MIT License. All of this puzzle’s model solutions are on GitHub and Hugging Face.

GPT-6 Astra Fewest cycles

80 cycles · 1 reactor · 15 symbolsquantum_2.80-1-15.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 → ← → ↑ ↓ ← S→ S↓ IN α GRAB B+ DROP SWAP OUT ω GRAB SWAP IN α

Running in the game

GPT-6 Astra solution running on quantum_2 in SpaceChem
SpaceChem Community Edition export (quantum_2.80-1-15.txt)
SOLUTION:QT-2,Player,0-0-0
COMPONENT:'drag-quantum-reactor-s',2,0,''
MEMBER:'instr-start',0,0,128,4,4,0,0
MEMBER:'instr-start',90,0,32,0,0,0,0
MEMBER:'feature-bonder',-1,0,1,7,4,0,0
MEMBER:'feature-bonder',-1,0,1,8,4,0,0
MEMBER:'feature-sensor',-1,0,1,3,3,0,0
MEMBER:'feature-tunnel',-1,0,1,2,1,0,0
MEMBER:'feature-tunnel',-1,0,1,6,4,0,0
MEMBER:'instr-arrow',0,0,64,6,4,0,0
MEMBER:'instr-arrow',180,0,64,8,4,0,0
MEMBER:'instr-input',-1,0,128,5,4,0,0
MEMBER:'instr-grab',-1,1,128,6,4,0,0
MEMBER:'instr-bond',-1,0,128,7,4,0,0
MEMBER:'instr-grab',-1,2,128,8,4,0,0
MEMBER:'instr-arrow',0,0,16,0,1,0,0
MEMBER:'instr-arrow',-90,0,16,0,3,0,0
MEMBER:'instr-arrow',90,0,16,2,1,0,0
MEMBER:'instr-arrow',180,0,16,2,3,0,0
MEMBER:'instr-swap',-1,0,32,0,1,0,0
MEMBER:'instr-output',-1,1,32,0,2,0,0
MEMBER:'instr-grab',-1,1,32,1,1,0,0
MEMBER:'instr-swap',-1,0,32,2,1,0,0
MEMBER:'instr-input',-1,0,32,2,2,0,0

Opus 5.5 Fewest reactors

82 cycles · 1 reactor · 12 symbolsquantum_2.82-1-12.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 → ← ↓ ↑ S← S↓ GRAB B+ OUT ω IN α SWAP GRAB SWAP DROP

Running in the game

Opus 5.5 solution running on quantum_2 in SpaceChem
SpaceChem Community Edition export (quantum_2.82-1-12.txt)
SOLUTION:QT-2,Player,0-0-0
COMPONENT:'drag-quantum-reactor-s',2,0,''
MEMBER:'instr-start',180,0,128,6,1,0,0
MEMBER:'instr-start',90,0,32,7,1,0,0
MEMBER:'feature-bonder',-1,0,1,7,4,0,0
MEMBER:'feature-bonder',-1,0,1,7,5,0,0
MEMBER:'feature-sensor',-1,0,1,5,7,0,0
MEMBER:'feature-tunnel',-1,0,1,1,1,0,0
MEMBER:'feature-tunnel',-1,0,1,7,3,0,0
MEMBER:'instr-arrow',0,0,64,1,1,0,0
MEMBER:'instr-arrow',180,0,64,5,1,0,0
MEMBER:'instr-grab',-1,1,128,2,1,0,0
MEMBER:'instr-bond',-1,0,128,3,1,0,0
MEMBER:'instr-output',-1,1,128,4,1,0,0
MEMBER:'instr-input',-1,0,128,5,1,0,0
MEMBER:'instr-arrow',90,0,16,7,3,0,0
MEMBER:'instr-arrow',-90,0,16,7,5,0,0
MEMBER:'instr-swap',-1,0,32,7,2,0,0
MEMBER:'instr-grab',-1,1,32,7,3,0,0
MEMBER:'instr-swap',-1,0,32,7,4,0,0
MEMBER:'instr-grab',-1,2,32,7,5,0,0

Opus 5.5 Fewest symbols

83 cycles · 1 reactor · 11 symbolsquantum_2.83-1-11.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 → ← ↓ ↑ S← S↑ GRAB B+ OUT ω IN α GRAB SWAP DROP

Running in the game

Opus 5.5 solution running on quantum_2 in SpaceChem
SpaceChem Community Edition export (quantum_2.83-1-11.txt)
SOLUTION:QT-2,Player,0-0-0
COMPONENT:'drag-quantum-reactor-s',2,0,''
MEMBER:'instr-start',180,0,128,7,1,0,0
MEMBER:'instr-start',-90,0,32,7,6,0,0
MEMBER:'feature-bonder',-1,0,1,7,4,0,0
MEMBER:'feature-bonder',-1,0,1,7,5,0,0
MEMBER:'feature-sensor',-1,0,1,5,7,0,0
MEMBER:'feature-tunnel',-1,0,1,1,1,0,0
MEMBER:'feature-tunnel',-1,0,1,7,3,0,0
MEMBER:'instr-arrow',0,0,64,1,1,0,0
MEMBER:'instr-arrow',180,0,64,5,1,0,0
MEMBER:'instr-grab',-1,1,128,2,1,0,0
MEMBER:'instr-bond',-1,0,128,3,1,0,0
MEMBER:'instr-output',-1,1,128,4,1,0,0
MEMBER:'instr-input',-1,0,128,5,1,0,0
MEMBER:'instr-arrow',90,0,16,7,3,0,0
MEMBER:'instr-arrow',-90,0,16,7,5,0,0
MEMBER:'instr-grab',-1,1,32,7,3,0,0
MEMBER:'instr-swap',-1,0,32,7,4,0,0
MEMBER:'instr-grab',-1,2,32,7,5,0,0