README.md

py-janaf: Python wrapper for NIST-JANAF Thermochemical Tables

Features

• Search compounds
• Parse a table as polars.DataFrame
• Fix some data
  • Fix missing sign
    • NOTE: Assuming the sign is consistent with the sign immediately following
  • Fix missing tab
    • NOTE: Based on PDF files
  • Ignore comment-like lines

Usage

pip install janaf

>>> import polars as pl
>>> import janaf
>>> table = janaf.search(formula="CO2$")
>>> table.name
'Carbon Dioxide (CO2)'
>>> table.formula
'C1O2(g)'
>>> table.df
shape: (62, 9)
┌────────┬────────┬─────────┬──────────────┬───┬───────────┬───────────┬─────────┬──────┐
│ T(K)   ┆ Cp     ┆ S       ┆ -[G-H(Tr)]/T ┆ … ┆ delta-f H ┆ delta-f G ┆ log Kf  ┆ Note │
│ ---    ┆ ---    ┆ ---     ┆ ---          ┆   ┆ ---       ┆ ---       ┆ ---     ┆ ---  │
│ f64    ┆ f64    ┆ f64     ┆ f64          ┆   ┆ f64       ┆ f64       ┆ f64     ┆ str  │
╞════════╪════════╪═════════╪══════════════╪═══╪═══════════╪═══════════╪═════════╪══════╡
│ 0.0    ┆ 0.0    ┆ 0.0     ┆ inf          ┆ … ┆ -393.151  ┆ -393.151  ┆ inf     ┆ null │
│ 100.0  ┆ 29.208 ┆ 179.009 ┆ 243.568      ┆ … ┆ -393.208  ┆ -393.683  ┆ 205.639 ┆ null │
│ 200.0  ┆ 32.359 ┆ 199.975 ┆ 217.046      ┆ … ┆ -393.404  ┆ -394.085  ┆ 102.924 ┆ null │
│ 298.15 ┆ 37.129 ┆ 213.795 ┆ 213.795      ┆ … ┆ -393.522  ┆ -394.389  ┆ 69.095  ┆ null │
│ …      ┆ …      ┆ …       ┆ …            ┆ … ┆ …         ┆ …         ┆ …       ┆ …    │
│ 5700.0 ┆ 64.68  ┆ 374.853 ┆ 317.953      ┆ … ┆ -417.658  ┆ -385.89   ┆ 3.536   ┆ null │
│ 5800.0 ┆ 64.772 ┆ 375.979 ┆ 318.944      ┆ … ┆ -418.541  ┆ -385.324  ┆ 3.47    ┆ null │
│ 5900.0 ┆ 64.865 ┆ 377.087 ┆ 319.92       ┆ … ┆ -419.445  ┆ -384.745  ┆ 3.406   ┆ null │
│ 6000.0 ┆ 64.957 ┆ 378.178 ┆ 320.882      ┆ … ┆ -420.372  ┆ -384.148  ┆ 3.344   ┆ null │
└────────┴────────┴─────────┴──────────────┴───┴───────────┴───────────┴─────────┴──────┘
>>> table.df.filter(pl.col("T(K)")==298.15).item(0, "delta-f H")  # kJ/mol
-393.522

Credit

Following files are distributed in NIST-JANAF Tables:

• py-janaf/janaf/janaf.json
• py-janaf/janaf/data/

NIST-JANAF Tables - Credits

NIST Standard Reference Database 13

NIST JANAF THERMOCHEMICAL TABLES 1985 Version 1.0

Data compiled and evaluated by M.W. Chase, Jr., C.A. Davies, J.R. Downey, Jr. D.J. Frurip, R.A. McDonald, and A.N. Syverud

Distributed by Standard Reference Data Program National Institute of Standards and Technology Gaithersburg, MD 20899

Copyright 1986 by the U.S. Department of Commerce on behalf of the United States. All rights reserved.

DISCLAIMER: NIST uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgement. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.