SpaceChem Bench: QT-4

quantum_5 Hard Quantum tunnels Single-reactor 63 Corvi · SpaceChem Bench report →

Inputs: α Methane (CH4), β Carbon (C). Output: ω Methane (CH4) ×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. 6 of 16 models solved it. Together they found 1 new Pareto-frontier point beyond the frozen community archive.

6 / 16models solved it
405best LLM cycles (246 community)
1new frontier point

Records

ScoreCommunity bestBest LLMModel
Cycles246405GPT-6.1 Sol · +65%
Reactors11Fable 5.1 Ties record
Symbols1821GPT-6 Astra · +17%

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

Lower is better ↙
Loading interactive Pareto explorer…
Community archiveModel frontier pointNew frontier point
Select a point with the mouse or keyboard to inspect its scores and reactor blueprint.

Search over time

Loading puzzle trajectories…

Every model

ModelSolvedBest cyclesBest reactorsBest symbolsNew frontier points
01GPT-6 AstraYes4321211
02GPT-6.1 SolYes405129—
03Sonnet 5.5Yes447133—
04Opus 5.5Yes559135—
05Fable 5.1Yes673141—
06Kimi K3.1 ProYes1,687166—
07DeepSeek V4.1 FlashNo————
08GLM-5.3No————
09GPT-6 LunaNo————
10Gemini 3.8 FlashNo————
11Gemini 4 ArgonNo————
12Grok 4.7No————
13Haiku 5.5No————
14MiMo-V2.6-ProNo————
15Muse Spark 1.3No————
16Muse Wonder 1.0No————

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-6.1 Sol Fewest cyclesFewest reactors

405 cycles · 1 reactor · 40 symbolsquantum_5.405-1-40.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 IN β SWAP DROP B+ CW DROP GRAB GRAB DROP GRAB CW SWAP ?H← IN α OUT ω SWAP

Running in the game

GPT-6.1 Sol solution running on quantum_5 in SpaceChem
SpaceChem Community Edition export (quantum_5.405-1-40.txt)
SOLUTION:QT-4,Player,0-0-0
COMPONENT:'drag-quantum-reactor-s',2,0,''
MEMBER:'instr-start',-90,0,128,1,7,0,0
MEMBER:'instr-start',0,0,32,3,2,0,0
MEMBER:'feature-bonder',-1,0,1,7,4,0,0
MEMBER:'feature-bonder',-1,0,1,7,5,0,0
MEMBER:'feature-sensor',-1,0,1,3,3,0,0
MEMBER:'feature-tunnel',-1,0,1,4,3,0,0
MEMBER:'feature-tunnel',-1,0,1,8,4,0,0
MEMBER:'instr-arrow',0,0,64,1,5,0,0
MEMBER:'instr-arrow',0,0,64,4,2,0,0
MEMBER:'instr-arrow',-90,0,64,4,3,0,0
MEMBER:'instr-arrow',-90,0,64,4,5,0,0
MEMBER:'instr-arrow',90,0,64,7,4,0,0
MEMBER:'instr-arrow',0,0,64,7,5,0,0
MEMBER:'instr-arrow',90,0,64,8,2,0,0
MEMBER:'instr-arrow',180,0,64,8,4,0,0
MEMBER:'instr-arrow',-90,0,64,8,5,0,0
MEMBER:'instr-grab',-1,1,128,1,5,0,0
MEMBER:'instr-input',-1,1,128,1,6,0,0
MEMBER:'instr-swap',-1,0,128,4,3,0,0
MEMBER:'instr-bond',-1,0,128,7,4,0,0
MEMBER:'instr-rotate',-1,0,128,7,5,0,0
MEMBER:'instr-grab',-1,1,128,8,4,0,0
MEMBER:'instr-grab',-1,2,128,8,5,0,0
MEMBER:'instr-arrow',0,0,16,1,1,0,0
MEMBER:'instr-arrow',-90,0,16,1,5,0,0
MEMBER:'instr-arrow',90,0,16,2,1,0,0
MEMBER:'instr-arrow',0,0,16,2,3,0,0
MEMBER:'instr-arrow',-90,0,16,2,4,0,0
MEMBER:'instr-arrow',90,0,16,3,3,0,0
MEMBER:'instr-arrow',0,0,16,3,4,0,0
MEMBER:'instr-arrow',0,0,16,4,3,0,0
MEMBER:'instr-arrow',-90,0,16,4,4,0,0
MEMBER:'instr-arrow',90,0,16,7,4,0,0
MEMBER:'instr-arrow',180,0,16,7,5,0,0
MEMBER:'instr-arrow',90,0,16,8,2,0,0
MEMBER:'instr-arrow',90,0,16,8,3,0,0
MEMBER:'instr-arrow',180,0,16,8,4,0,0
MEMBER:'instr-grab',-1,1,32,1,1,0,0
MEMBER:'instr-rotate',-1,0,32,2,3,0,0
MEMBER:'instr-swap',-1,0,32,3,3,0,0
MEMBER:'instr-sensor',180,0,32,3,4,0,1
MEMBER:'instr-grab',-1,2,32,4,3,0,0
MEMBER:'instr-input',-1,0,32,6,5,0,0
MEMBER:'instr-output',-1,1,32,7,3,0,0
MEMBER:'instr-grab',-1,2,32,7,5,0,0
MEMBER:'instr-swap',-1,0,32,8,3,0,0
MEMBER:'instr-grab',-1,1,32,8,4,0,0

GPT-6 Astra Fewest symbols★ New frontier point

617 cycles · 1 reactor · 21 symbolsquantum_5.617-1-21.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→ OUT ω GRAB IN α DROP ?H← CW IN β SWAP GRAB B+ DROP GRAB CW

Running in the game

GPT-6 Astra solution running on quantum_5 in SpaceChem
SpaceChem Community Edition export (quantum_5.617-1-21.txt)
SOLUTION:QT-4,Player,0-0-0
COMPONENT:'drag-quantum-reactor-s',2,0,''
MEMBER:'instr-start',-90,0,128,1,6,0,0
MEMBER:'instr-start',0,0,32,4,1,0,0
MEMBER:'feature-bonder',-1,0,1,7,3,0,0
MEMBER:'feature-bonder',-1,0,1,7,4,0,0
MEMBER:'feature-sensor',-1,0,1,6,4,0,0
MEMBER:'feature-tunnel',-1,0,1,1,5,0,0
MEMBER:'feature-tunnel',-1,0,1,7,2,0,0
MEMBER:'instr-arrow',90,0,64,0,3,0,0
MEMBER:'instr-arrow',0,0,64,0,5,0,0
MEMBER:'instr-arrow',0,0,64,1,1,0,0
MEMBER:'instr-arrow',-90,0,64,1,5,0,0
MEMBER:'instr-arrow',90,0,64,2,1,0,0
MEMBER:'instr-arrow',-90,0,64,2,6,0,0
MEMBER:'instr-output',-1,1,128,0,3,0,0
MEMBER:'instr-grab',-1,1,128,1,1,0,0
MEMBER:'instr-input',-1,0,128,1,2,0,0
MEMBER:'instr-grab',-1,2,128,1,5,0,0
MEMBER:'instr-sensor',180,0,128,2,3,0,1
MEMBER:'instr-rotate',-1,0,128,2,6,0,0
MEMBER:'instr-arrow',90,0,16,7,1,0,0
MEMBER:'instr-arrow',-90,0,16,7,6,0,0
MEMBER:'instr-input',-1,1,32,6,1,0,0
MEMBER:'instr-swap',-1,0,32,7,1,0,0
MEMBER:'instr-grab',-1,1,32,7,2,0,0
MEMBER:'instr-bond',-1,0,32,7,3,0,0
MEMBER:'instr-grab',-1,2,32,7,4,0,0
MEMBER:'instr-grab',-1,1,32,7,5,0,0
MEMBER:'instr-rotate',-1,0,32,7,6,0,0