lamm-mit/nistwebbook

NIST Chemistry WebBook

Query the NIST Chemistry WebBook for thermochemical, spectral, and property data. Data are from NIST Standard Reference Database 69.

Overview

• Search by compound name, chemical formula, CAS Registry Number, or InChI/InChIKey
• Retrieve thermochemistry, IR/MS/UV-Vis spectra, gas chromatography, and basic properties
• Optional: install nistchempy for full programmatic search; otherwise script prints WebBook URLs for manual lookup

Usage

Search by name (requires nistchempy)

python3 {baseDir}/scripts/nistwebbook_search.py --query "water"

Look up by CAS number (requires nistchempy)

python3 {baseDir}/scripts/nistwebbook_search.py --cas "7732-18-5"

Get WebBook URL only (no nistchempy needed)

python3 {baseDir}/scripts/nistwebbook_search.py --query "methane" --url-only

Limit results

python3 {baseDir}/scripts/nistwebbook_search.py --query "ethanol" --max-results 3

Parameters

| Parameter | Description | Default | |-----------|-------------|---------| | --query | Compound name or formula | - | | --cas | CAS Registry Number (e.g. 7732-18-5) | - | | --max-results | Max compounds to return | 5 | | --url-only | Only print NIST WebBook search URL (no nistchempy) | false | | --format | summary or json | summary |

Output

• Summary: Name, formula, CAS RN, molecular weight; links to thermochemistry/spectra on WebBook
• JSON: Structured data when using nistchempy
• Without nistchempy: script prints the WebBook search URL so users can open it in a browser

Notes

• Install for full search: pip install nistchempy (also needs requests, bs4, pandas)
• NIST does not provide an official API; nistchempy is an unofficial wrapper
• Reference: NIST Chemistry WebBook