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

---

NIST policy on privacy, security, and accessibility.

---

© 2013 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

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 [email protected].

II.C.1. (XV.B.)

Thermodynamic reference states.

Integrated Heat Capacity (H(298)-H(0)) in kJ mol^-1

Element	Reference State	H(298)-H(0)	unc.
H	H2, g	8.468	0.001
D	D2, g	8.569
He	He, g	6.197
Li	Li, cr	4.632	0.040
Be	Be, cr	1.950	0.020
B	B, cr	1.222	0.008
C	C, cr graphite	1.050	0.020
N	N2, g	8.670	0.001
O	O2, g	8.680	0.002
F	F2, g	8.825	0.001
Ne	Ne, g	6.197
Na	Na, cr	6.460	0.020
Mg	Mg, cr	4.998	0.030
Al	Al, cr	4.540	0.020
Si	Si, cr	3.217	0.008
P	P, cr white	5.360	0.002
S	S, cr rhombic	4.412	0.006
Cl	Cl2, g	9.181	0.001
Ar	Ar, g	6.197
K	K, cr	7.082
Ti	Ti, cr	4.824	0.015
Cu	Cu, cr	5.004	0.008
Br	Br2, l	24.520	0.010
Kr	Kr, g	6.197
Xe	Xe, g	6.197

Data from CODATA
Cox, J.D.; Wagman, D.D.; Medvedev, V.A.CODATA Key Values for Thermodynamics. Hemisphere, New York, 1989

For gas-phase species with well defined enthalpies of formation that are useful in calculating reactions see section VII.C.2 Species with well-known enthalpies of formation

---

Please send comments
email: [email protected]