nispo 0.1.6

SMILES to IUPAC naming tool optimized by OPSIN roundtrip benchmarks.

NISPO

NISPO is an open-source, RDKit-based Python package for generating IUPAC names of molecules. Generated names are designed to pass an OPSIN round-trip test, in which OPSIN parses the name back to the same molecular structure. The entire NISPO codebase was generated by OpenAI Codex using GPT-5.5.

Installation

pip install nispo

NISPO requires Python 3.10 or newer.

Quick start

Use smiles_to_iupac to convert a single SMILES string, or smiles_to_iupac_batch to convert multiple SMILES strings at once:

from nispo import smiles_to_iupac, smiles_to_iupac_batch

smiles_to_iupac("CCO")
# 'ethanol'

smiles_to_iupac_batch(["CCO", "not-a-smiles"])
# ['ethanol', '']

Unsuccessful conversions return an empty string (""). Batch conversion preserves the number and order of the inputs.

Performance

NISPO achieved 98.1% OPSIN round-trip accuracy on a held-out benchmark of 103 million PubChem compounds. It is optimized for OPSIN round-trip validity rather than preferred IUPAC nomenclature, so generated names may differ from names listed in databases.

Citation

If you use NISPO in your work, please cite:

@article{runcie2026nispo,
  title   = {NISPO: Open-source IUPAC name generation tool},
  author  = {Runcie, Nicholas T. and Imrie, Fergus and Deane, Charlotte M.},
  journal = {},
  year    = {},
  doi     = {}
}

OPSIN is described in Lowe, D. M.; Corbett, P. T.; Murray-Rust, P.; Glen, R. C. Chemical Name to Structure: OPSIN, an Open Source Solution. Journal of Chemical Information and Modeling 2011, 51 (3), 739–753. https://doi.org/10.1021/ci100384d.

License

NISPO is released under the BSD 3-Clause License. See LICENSE.

AI disclosure

This repository was developed using OpenAI Codex. The codebase is AI-generated and was created through an autonomous self-iteration process: Codex repeatedly ran the benchmark, inspected failures, updated the implementation, and reran the benchmark until high OPSIN round-trip accuracy was achieved.