National Institute of Standards and Technology

Computational Chemistry Comparison and Benchmark DataBase
Release 22	May 2022
NIST Standard Reference Database 101

I	Introduction
II	Experimental data
III	Calculated data
IV	Data comparisons
V	Cost comparisons
VI	Input and output files
VII	Tutorials and Units
VIII	Links to other sites
IX	Feedback
X	Older CCCBDB versions
XII	Geometries
XIII	Vibrations
XIV	Reaction data
XV	Entropy data
XVI	Bibliographic data
XVII	Ion data
XVIII	Bad calculations
XIX	Index of properties
XX	H-bond dimers
XXI	Oddities

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The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

Please send questions, comments, corrections, additions and suggestions to cccbdb@nist.gov.

IV.A.1. (XIV.A.)

Reaction Enthalpy Comparison

Enter species formula

Reactants			Products
Formula	Name	CAS no.	Formula	Name	CAS no.

Rules for chemical formulas
Enter a sequence of element symbols followed by numbers to specify the amounts of desired elements (e.g., C6H6).
Elements may be in any order.
If only one of a given atom is desired, you may omit the number after the element symbol.
Parentheses may be used to group atoms.
Multiple specifications for an atom will be added. This means that CH3(CH2)4CH3 will be treated the same as C6H14.
The reaction enthalpy pages only work with neutral species in their ground electronic state.