Native Compute and Chemical Space
Burette ships a native Apple Silicon compute layer: a CPU reference backend with Metal GPU acceleration, running in a separate verified compute service next to the app. Unlike xTB or CREST, it needs no external installation.
Clustering runs are cancellable mid-job. Every job records its provenance and
reports which backend actually executed it: Metal GPU only when the GPU path
really ran, otherwise reference CPU.
Clustering and similarity
The collection grid exposes compute actions over the current scope:
- Cluster selected / Cluster filtered / Cluster all — Tanimoto-cutoff clustering over the selected rows, the active filter result, or the whole collection. Scope is frozen before the job starts, so edits during a run cannot corrupt the result.
- Find similar — exact top-ranked similarity search that reuses the verified fingerprints from a previous clustering run.
- Export diverse — an immutable diverse-subset export with structures, a table, and provenance.
Conformers and optimization
The collection grid’s Generate 3D action (for selected molecules) and the Ketcher Compute menu generate conformer ensembles natively (distance geometry, ETKDG-style optimization, MMFF94/MMFF94s refinement, and stereochemistry validation). The 3D engine, candidate count, and RMSD threshold are configurable in Settings.
Alignment and scoring compare poses with RMSD, shape, and electrostatic terms.
Semiempirical energies
Single-point semiempirical energies (including RM1, AM1, and PM6) run through the same native service and produce readable reports with method and provenance details.
Chemical Space
The Chemical Space panel projects a collection into an interactive 2D/3D map:
- Metal-accelerated embeddings (UMAP) over molecular representations
- clustering directly in the projected space
- activity colouring from a numeric column
- activity-cliff highlighting for similar molecules with divergent activity
Selections in the map stay linked to the grid, so you can lasso a region and continue working with those rows.
Boundaries
- Native compute runs in the desktop app; Finder Quick Look and the iPhone app stay preview-only surfaces.
- External engines remain separate: xTB and CREST/PRISM are still local executables with their own pages.