Reference problems
$13.196
total bounty at launch
$9.531
largest bounty
10
reference problems
$0.007
median witness check
Each card will become a frozen problem record: the structure, the exact solver parameters, and the acceptance thresholds, hashed at posting. The first submission that passes verification takes the bounty.
Bulk MgO, rocksalt SCF
SCFreasonable
compcheminsulator
| Atoms | 4 Mg · 4 O (8) |
| Cell | 4.21 Å cubic |
| Engine | SIESTA |
| Electrons | no spin · SR pseudos |
$0.000bountywitness check ~$0.003 · open 3 d
Bulk Fe, ferromagnetic relax
RELAXconservative
compchemmetalmagnetic
| Atoms | 16 Fe |
| Cell | 5.74 Å cubic (2×2×2) |
| Engine | QE |
| Electrons | collinear FM · SR pseudos |
$0.212bountywitness check ~$0.013 · open 5 d
SrTiO₃ 3×3×3, O-vacancy relaxation
RELAXreasonable
compchemdefectperovskite
| Atoms | 27 Sr · 27 Ti · 80 O (134) |
| Cell | 11.72 Å cubic supercell |
| Engine | SIESTA |
| Electrons | no spin · SR pseudos |
| Constraints | outer shell fixed |
$0.047bountywitness check ~$0.006 · open 7 d
NiO, noncollinear + SOC + U single point
SCFhighly_conservative
compchemcorrelatedsoc
| Atoms | 32 Ni · 32 O (64) |
| Cell | 8.34 Å cubic (2×2×2) |
| Engine | QE |
| Electrons | noncollinear AFM-II · SOC · +U on Ni 3d · FR pseudos |
$1.503bountywitness check ~$0.041 · open 14 d
Co(110) slab, in-plane relax with z fixed
RELAXreasonable
compchemslabmagneticsoc
| Atoms | 63 Co (3×3, 7 layers) |
| Cell | fcc(110) surface cell · 12 Å vacuum |
| Engine | QE |
| Electrons | noncollinear FM · SOC · FR pseudos |
| Constraints | z fixed, relax x and y |
$9.531bountywitness check ~$0.405 · open 10 d
Fe/MgO/Fe tunnel junction, antiparallel state
SCFconservative
heterostructuremagneticspintronics
| Atoms | 48 Fe · 20 Mg · 20 O (88) |
| Cell | 5.73 × 5.73 × 28.6 Å superlattice |
| Stack | Fe(6) / MgO(5) / Fe(6), MgO strained 3.8% to Fe |
| Engine | SIESTA |
| Electrons | collinear, electrodes antiparallel · SR pseudos |
$1.605bountywitness check ~$0.021 · open 21 d
Au/MoS₂/Au memristor, Au in the S vacancy
RELAXconservative
heterostructurememristor2D
| Atoms | 41 Au · 3 Mo · 5 S (49) |
| Cell | 5.62 Å hexagonal × 29.2 Å superlattice |
| Stack | Au(111)₅ / MoS₂ monolayer / Au(111)₅, leads continuous across the cell |
| Interface | √3×√3 MoS₂ on 2×2 Au(111); 5.4% mismatch split +2.7% / −2.6% |
| Engine | SIESTA |
| Functional | PBE + dispersion correction |
| Electrons | no spin · SR pseudos |
| Constraints | boundary Au layers fixed |
$0.216bountywitness check ~$0.005 · open 14 d
Succinic acid crystal, molecular relax
RELAXreasonable
organicmolecular crystalvdW
| Atoms | 8 C · 12 H · 8 O (28, 2 molecules) |
| Cell | 5.47 × 8.74 × 5.11 Å |
| Engine | SIESTA |
| Functional | PBE + dispersion correction |
| Electrons | no spin · SR pseudos |
$0.001bountywitness check ~$0.003 · open 7 d
CO on Pt(111), adsorption geometry
RELAXconservative
surfacecatalysismetal
| Atoms | 36 Pt · 1 C · 1 O (38) |
| Cell | 3×3 slab, 4 layers · 14 Å vacuum |
| Engine | QE |
| Electrons | no spin · SR pseudos |
| Constraints | bottom 2 layers fixed |
$0.082bountywitness check ~$0.009 · open 10 d
Polyethylene chain, 1D periodic relax
RELAXreasonable
organicpolymervdW
| Atoms | 8 C · 16 H (24, 4 repeat units) |
| Cell | 10.2 Å chain repeat · 12 Å vacuum ⊥ |
| Engine | SIESTA |
| Functional | PBE + dispersion correction |
| Electrons | no spin · SR pseudos |
$0.000bountywitness check ~$0.003 · open 5 d
Reading a card.
Bounty is 90% of what a competent solve costs on the platform's own cost model,
and the same rule applies whichever engine the problem is posted with: a cheap
local-orbital pre-solve to converge the geometry and seed the density, then a plane-wave
finish, priced by the number of QE SCF steps that finish takes. A solver that runs cold
plane waves from scratch loses money. A solver that beats the reference workflow keeps
the difference.
Witness check is what one verification of a submitted solution costs the
platform: a few SCF steps from the submitted density, not a full re-solve.
Fidelity names the acceptance policy. The numbers behind it are set at posting
and not negotiable afterwards.
allowMoreAccurate is on for every card: a
solution converged tighter than the frozen floor settles on the same terms.
Electrons is the electronic treatment. Constraints are geometric only.
Open is the listing window after posting.
Every number here is produced by scripts/reference_systems.py in the repo.