qwen3.8-max-0902 · round 1 · seed 2$0.59MP4caffeine.pdb
caffeine.pdb · 53 lines
HEADER    SMALL MOLECULE
COMPND    CAFFEINE (1,3,7-TRIMETHYLXANTHINE, C8H10N4O2)
AUTHOR    BUILT GEOMETRICALLY
HETATM    1  N1  CFF A   1      -0.721   1.463  -0.741  1.00  0.00           N
HETATM    2  C2  CFF A   1      -1.529   1.167   0.363  1.00  0.00           C
HETATM    3  N3  CFF A   1      -1.234   0.063   1.171  1.00  0.00           N
HETATM    4  C4  CFF A   1      -0.129  -0.746   0.875  1.00  0.00           C
HETATM    5  C5  CFF A   1       0.679  -0.450  -0.229  1.00  0.00           C
HETATM    6  C6  CFF A   1       0.383   0.654  -1.037  1.00  0.00           C
HETATM    7  O2  CFF A   1      -2.500   1.877   0.623  1.00  0.00           O
HETATM    8  O6  CFF A   1       1.087   0.912  -1.999  1.00  0.00           O
HETATM    9  N7  CFF A   1       1.642  -1.438  -0.204  1.00  0.00           N
HETATM   10  C8  CFF A   1       1.434  -2.243   0.809  1.00  0.00           C
HETATM   11  N9  CFF A   1       0.340  -1.860   1.520  1.00  0.00           N
HETATM   12  C10 CFF A   1      -1.028   2.606  -1.579  1.00  0.00           C
HETATM   13  C11 CFF A   1      -2.077  -0.246   2.323  1.00  0.00           C
HETATM   14  C12 CFF A   1       2.740  -1.569  -1.172  1.00  0.00           C
HETATM   15  H8  CFF A   1       2.050  -3.097   1.047  1.00  0.00           H
HETATM   16 H10A CFF A   1      -1.510   3.377  -0.978  1.00  0.00           H
HETATM   17 H10B CFF A   1      -0.106   3.001  -2.005  1.00  0.00           H
HETATM   18 H10C CFF A   1      -1.698   2.299  -2.382  1.00  0.00           H
HETATM   19 H11A CFF A   1      -1.476  -0.728   3.094  1.00  0.00           H
HETATM   20 H11B CFF A   1      -2.504   0.676   2.718  1.00  0.00           H
HETATM   21 H11C CFF A   1      -2.880  -0.916   2.016  1.00  0.00           H
HETATM   22 H12A CFF A   1       3.016  -0.582  -1.544  1.00  0.00           H
HETATM   23 H12B CFF A   1       3.601  -2.027  -0.685  1.00  0.00           H
HETATM   24 H12C CFF A   1       2.418  -2.194  -2.004  1.00  0.00           H
CONECT    1    2    6   12
CONECT    2    1    3    7
CONECT    3    2    4   13
CONECT    4    3    5   11
CONECT    5    4    6    9
CONECT    6    5    1    8
CONECT    7    2
CONECT    8    6
CONECT    9   10    5   14
CONECT   10   11    9   15
CONECT   11    4   10
CONECT   12    1   16   17   18
CONECT   13    3   19   20   21
CONECT   14    9   22   23   24
CONECT   15   10
CONECT   16   12
CONECT   17   12
CONECT   18   12
CONECT   19   13
CONECT   20   13
CONECT   21   13
CONECT   22   14
CONECT   23   14
CONECT   24   14
END
gallery/A caffeine molecule in 3D/Qwen3.8 Max, run 2

Right on the first render, then still checking it when the clock ran out.

modelqwen/qwen3.8-max-0902taskpdb-caffeine@v1date2026-09-21rounds1 of 8 allowedcost$0.5944thinkingmediumtokens1,098,165 in, 29,072 out, of which 18,260 reasoningtime12 min 0 s

What the harness did to this run. The 12-minute clock ended it before the model finished, so this is where it had got to when time ran out.

C8H10N4O2decided by a number, from the filepass
Fused purine coredecided by a number, from the filepass
Methyls on N1, N3, N7decided by a number, from the filepass
Carbonyls at C2 and C6decided by a number, from the filepass
Flat rings, real bond lengthsdecided by a number, from the filepass

There is no post about this one, since only some results need one, so the picture, the source and the scoring are here instead.

its other runs
A caffeine molecule in 3D, by Qwen3.8 Max, run 1run 1 · 6r · $0.6292Textbook caffeine, flat to within a thousandth of an ångström.A caffeine molecule in 3D, by Qwen3.8 Max, run 1run 1 · 2r · $0.4734Caffeine again, bond for bond, in two rounds.A caffeine molecule in 3D, by Qwen3.8 Max, run 3run 3 · 1r · $0.3614Right on the first render, and it stopped there.
same prompt, other modelsall 9 runs on A caffeine molecule in 3D →
the prompt it was given
Write a PDB file with 3D coordinates for a caffeine molecule, hydrogens included.
Frozen at v1. This model got this and nothing else.
ground truth

Caffeine, C8H10N4O2: a purine core, a six-membered ring fused to a five-membered ring across two shared carbons, methyls on N1, N3 and N7, carbonyl oxygens at C2 and C6, and the whole ring system flat. How it is scored, and this run's files on GitHub.