Chemistry Module
The chemistry module provides cheminformatics utilities for NMR workflows, including HOSE (Hierarchically Ordered Spherical Environment) code generation.
Base path: /latest/chem
Endpoints
GET /hosecode
Generate HOSE codes for every atom in a molecule.
Query parameters:
| Parameter | Default | Description |
|---|---|---|
smiles | required | SMILES string (e.g. CCCC1CC1) |
framework | cdk | cdk or rdkit |
spheres | 3 | Number of bond spheres (1–10) |
usestereo | false | Include stereochemistry (CDK only) |
Response: Array of HOSE code strings, one per atom.
bash
curl "https://dev.nmrkit.nmrxiv.org/latest/chem/hosecode?smiles=CCO&framework=cdk&spheres=3"Example response:
json
[
"C(CC,CC,&)",
"C(CC,C&,&)",
"C(CC,CC,&)"
]Frameworks
| Framework | Library | Stereo support |
|---|---|---|
cdk | Chemistry Development Kit | Yes (usestereo) |
rdkit | RDKit | No |
HOSE codes encode the local chemical environment around each atom and are widely used in NMR chemical shift prediction and database lookup.
Error codes
| Status | Meaning |
|---|---|
409 | Molecule already exists (unique constraint) |
422 | Invalid SMILES or parse error |
See also
- Prediction module — structure-based spectrum prediction
- nmr-respredict service — HOSE-based residual prediction