ATcT [1, 2] enthalpies of formation based on version 1.122p of the Thermochemical Network [3]

Below is a list of 0 K and 298.15 K enthalpies of formation for all 1727 species included in version 1.122p.
This version of ATcT results was generated from an expansion of version 1.122o [4] to include an updated enthalpy of formation for Hydrazine. [5].

The elements in their standard states are listed first; the listing order of the other species follows the actual order from the ATcT solution file, which roughly reflects the number of thermochemically-relevant determinations that include the species in question (highest first). The intent is to convey a very approximate indication of the robustness of the listed values, which is generally higher toward the top of the list and lower toward the bottom.

For species other than elements in their standard states, the Species Name acts as a link to the page itemizing the most important contributors to the provenance of its ATcT enthalpy of formation, other highly correlated chemical species, and high-leverage reactions in the Thermochemical Network.
(Please note that, as opposed to traditional sequential thermochemistry where the provenance of a given enthalpy of formation is typically a single measurement, the provenances of ATcT enthalpies of formation, which are obtained by analysing and solving a large Thermochemical Network, are normally quite distributed.)

If you find Active Thermochemical Tables useful in your research, please cite this website as given in Ref. [3], and, if possible, the ATcT approach as given in Refs. [1] and [2].

Species:

(chemical formulas are case sensitive)

Exact Matches only:

Website functionality credits

The stoichiometry represents fractions as decimals,
e.g. 0.5 O2, 1 H2, 1 H2O would represent
1/2 O2 + H2 → H2O

Species Name	Image	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
Dihydrogen		0	0	exact		2.01588 ± 0.00014	1333-74-0*0
Helium		0	0	exact		4.0026020 ± 0.0000020	7440-59-7*0
Carbon atom		0	0	exact		12.01070 ± 0.00080	7440-44-0*500
Dinitrogen		0	0	exact		28.01348 ± 0.00014	7727-37-9*0
Dioxygen		0	0	exact		31.99880 ± 0.00060	7782-44-7*0
Difluorine		0	0	exact		37.9968064 ± 0.0000010	7782-41-4*0
Neon		0	0	exact		20.17970 ± 0.00060	7440-01-9*0
Dichlorine		0	0	exact		70.9054 ± 0.0018	7782-50-5*0
Argon		0	0	exact		39.94800 ± 0.00100	7440-37-1*0
Dibromine		0	0	exact		159.8080 ± 0.0020	7726-95-6*500
Krypton		0	0	exact		83.8000 ± 0.1000	7439-90-9*0
Diiodine		0	0	exact		253.808940 ± 0.000060	7553-56-2*500
Xenon		0	0	exact		131.2900 ± 0.0200	7440-63-3*0
Deuterium molecule		0	0	exact		4.02820355600 ± 0.00000000080	7782-39-0*0
Hydrogen atom		216.034	217.998	± 0.000	kJ/mol	1.007940 ± 0.000070	12385-13-6*0
Carbon atom		711.397	716.882	± 0.047	kJ/mol	12.01070 ± 0.00080	7440-44-0*0
Oxygen atom		246.844	249.229	± 0.0021	kJ/mol	15.99940 ± 0.00030	17778-80-2*0
Nitrogen atom		470.579	472.441	± 0.024	kJ/mol	14.006740 ± 0.000070	17778-88-0*0
Carbon dioxide		-393.108	-393.474	± 0.015	kJ/mol	44.00950 ± 0.00100	124-38-9*0
Chlorine atom		119.621	121.302	± 0.0011	kJ/mol	35.45270 ± 0.00090	22537-15-1*0
Methane		-66.561	-74.530	± 0.055	kJ/mol	16.04246 ± 0.00085	74-82-8*0
Fluorine atom		77.258	79.364	± 0.048	kJ/mol	18.99840320 ± 0.00000050	14762-94-8*0
Ethane		-68.36	-83.98	± 0.13	kJ/mol	30.0690 ± 0.0017	74-84-0*0
Water		-286.302	-285.830	± 0.026	kJ/mol	18.01528 ± 0.00033	7732-18-5*500
Water		-238.933	-241.836	± 0.026	kJ/mol	18.01528 ± 0.00033	7732-18-5*0
Hydron		1528.084	1530.047	± 0.000	kJ/mol	1.007391 ± 0.000070	12408-02-5*0
Ethylene		60.87	52.35	± 0.12	kJ/mol	28.0532 ± 0.0016	74-85-1*0
Bromine atom		117.914	111.851	± 0.056	kJ/mol	79.90400 ± 0.00100	10097-32-2*0
Methanol		-190.04	-200.92	± 0.15	kJ/mol	32.04186 ± 0.00090	67-56-1*0
Methyl		149.867	146.453	± 0.059	kJ/mol	15.03452 ± 0.00083	2229-07-4*0
Hydrogen chloride		-91.989	-92.173	± 0.0062	kJ/mol	36.46064 ± 0.00090	7647-01-0*0
Carbon monoxide		-113.803	-110.523	± 0.026	kJ/mol	28.01010 ± 0.00085	630-08-0*0
Hydroxyl		37.248	37.488	± 0.026	kJ/mol	17.00734 ± 0.00031	3352-57-6*0
Formaldehyde		-105.377	-109.215	± 0.097	kJ/mol	30.02598 ± 0.00087	50-00-0*0
Propane		-82.76	-105.04	± 0.18	kJ/mol	44.0956 ± 0.0025	74-98-6*0
Hydrogen fluoride		-272.674	-272.721	± 0.049	kJ/mol	20.006343 ± 0.000070	7664-39-3*0
Ethanol		-217.31	-235.03	± 0.22	kJ/mol	46.0684 ± 0.0017	64-17-5*0
Hydrogen bromide		-27.94	-35.79	± 0.14	kJ/mol	80.9119 ± 0.0010	10035-10-6*0
Iodine		107.157	106.757	± 0.0021	kJ/mol	126.904470 ± 0.000030	14362-44-8*0
Acetylene		228.82	228.26	± 0.13	kJ/mol	26.0373 ± 0.0016	74-86-2*0
Ethyl		131.04	119.98	± 0.27	kJ/mol	29.0611 ± 0.0016	2025-56-1*0
Hydrogen cyanide		129.663	129.278	± 0.090	kJ/mol	27.02538 ± 0.00081	74-90-8*0
Nitric oxide		90.617	91.121	± 0.065	kJ/mol	30.00614 ± 0.00031	10102-43-9*0
Chloromethane		-74.63	-82.56	± 0.19	kJ/mol	50.4872 ± 0.0012	74-87-3*0
Ammonia		-38.564	-45.557	± 0.029	kJ/mol	17.03056 ± 0.00022	7664-41-7*0
Propene		34.92	19.92	± 0.21	kJ/mol	42.0797 ± 0.0024	115-07-1*0
Nitrogen dioxide		36.856	34.049	± 0.065	kJ/mol	46.00554 ± 0.00060	10102-44-0*0
Hydrogen iodide		28.645	26.470	± 0.036	kJ/mol	127.912410 ± 0.000076	10034-85-2*0
Hydroxyde		-139.093	-139.060	± 0.026	kJ/mol	17.00789 ± 0.00031	14280-30-9*0
Benzene		100.61	83.10	± 0.23	kJ/mol	78.1118 ± 0.0048	71-43-2*0
Acetaldehyde		-155.12	-165.60	± 0.26	kJ/mol	44.0526 ± 0.0017	75-07-0*0
Dioxidanyl		15.12	12.22	± 0.15	kJ/mol	33.00674 ± 0.00060	3170-83-0*0
Fluoromethane		-227.46	-235.49	± 0.23	kJ/mol	34.03292 ± 0.00083	593-53-3*0
Hydrogen peroxide		-129.480	-135.466	± 0.063	kJ/mol	34.01468 ± 0.00062	7722-84-1*0
Bromomethane		-20.86	-36.26	± 0.18	kJ/mol	94.9385 ± 0.0013	74-83-9*0
n-Butane		-98.47	-125.78	± 0.25	kJ/mol	58.1222 ± 0.0033	106-97-8*0
Methylene		391.061	391.618	± 0.097	kJ/mol	14.02658 ± 0.00081	2465-56-7*1
Methylene		428.72	429.13	± 0.11	kJ/mol	14.02658 ± 0.00081	2465-56-7*2
Hypochlorous acid		-73.870	-76.809	± 0.027	kJ/mol	52.46004 ± 0.00095	7790-92-3*0
Propyne		192.77	185.71	± 0.24	kJ/mol	40.0639 ± 0.0024	74-99-7*0
Formic acid		-371.11	-378.42	± 0.22	kJ/mol	46.0254 ± 0.0010	64-18-6*1
Dibromine		45.68	30.88	± 0.11	kJ/mol	159.8080 ± 0.0020	7726-95-6*0
Tetrachloromethane		-93.41	-95.58	± 0.43	kJ/mol	153.8215 ± 0.0037	56-23-5*0
Methylamine		-6.67	-21.38	± 0.27	kJ/mol	31.05714 ± 0.00088	74-89-5*0
Fluoride		-250.907	-249.122	± 0.048	kJ/mol	18.99895178 ± 0.00000050	16984-48-8*0
Ketene		-45.35	-48.47	± 0.12	kJ/mol	42.0367 ± 0.0016	463-51-4*0
Tetrafluoromethane		-927.50	-933.47	± 0.25	kJ/mol	88.00431 ± 0.00080	75-73-0*0
Chloroethane		-96.90	-111.49	± 0.26	kJ/mol	64.5138 ± 0.0019	75-00-3*0
Vinyl		301.16	296.96	± 0.33	kJ/mol	27.0452 ± 0.0016	2669-89-8*0
Acetone		-200.08	-216.77	± 0.36	kJ/mol	58.0791 ± 0.0025	67-64-1*0
Methylidyne		592.820	596.154	± 0.099	kJ/mol	13.01864 ± 0.00080	3315-37-5*0
Methoxide		-122.64	-130.37	± 0.30	kJ/mol	31.03447 ± 0.00088	3315-60-4*0
Acetonitrile		81.09	74.04	± 0.25	kJ/mol	41.0520 ± 0.0016	75-05-8*0
Oxonium		605.84	599.09	± 0.17	kJ/mol	19.02267 ± 0.00037	13968-08-6*0
Ozone		144.397	141.735	± 0.039	kJ/mol	47.99820 ± 0.00090	10028-15-6*0
Diiodine		65.497	62.417	± 0.0041	kJ/mol	253.808940 ± 0.000060	7553-56-2*0
Phenyl		350.35	336.99	± 0.53	kJ/mol	77.1039 ± 0.0048	2396-01-2*0
Toluene		73.29	50.01	± 0.34	kJ/mol	92.1384 ± 0.0056	108-88-3*0
Fluoroform		-689.03	-695.98	± 0.41	kJ/mol	70.01385 ± 0.00080	75-46-7*0
Trifluoromethyl		-464.96	-467.76	± 0.48	kJ/mol	69.00591 ± 0.00080	2264-21-3*0
Ethylium		914.84	902.76	± 0.31	kJ/mol	29.0606 ± 0.0016	14936-94-8*0
Nitrilomethyl		436.75	440.04	± 0.14	kJ/mol	26.01744 ± 0.00080	2074-87-5*0
1,3-Butadiene		125.30	110.82	± 0.36	kJ/mol	54.0904 ± 0.0032	106-99-0*0
Phenol		-74.66	-93.26	± 0.64	kJ/mol	94.1112 ± 0.0048	108-95-2*0
Chloride		-228.953	-227.346	± 0.0021	kJ/mol	35.45325 ± 0.00090	16887-00-6*0
Bromide		-206.623	-212.685	± 0.056	kJ/mol	79.90455 ± 0.00100	24959-67-9*0
Hypobromous acid		-51.61	-62.08	± 0.47	kJ/mol	96.9113 ± 0.0010	13517-11-8*0
Methoxy		28.82	21.45	± 0.29	kJ/mol	31.03392 ± 0.00088	2143-68-2*0
Formyl		41.393	41.770	± 0.097	kJ/mol	29.01804 ± 0.00086	2597-44-6*0
Acetic acid		-418.86	-432.98	± 0.43	kJ/mol	60.0520 ± 0.0017	64-19-7*1
Hydroxymethyl		-10.44	-16.75	± 0.28	kJ/mol	31.03392 ± 0.00088	2597-43-5*0
Chlorooxidanyl		101.125	101.716	± 0.035	kJ/mol	51.45210 ± 0.00095	14989-30-1*0
Oxomethylium		827.769	827.184	± 0.097	kJ/mol	29.01749 ± 0.00086	17030-74-9*0
Allene		197.32	189.83	± 0.25	kJ/mol	40.0639 ± 0.0024	463-49-0*0
Imidogen		358.74	358.78	± 0.17	kJ/mol	15.014680 ± 0.000099	13774-92-0*0
Dioxymethyl	$[O-]\[O+]=C$	111.89	104.89	± 0.63	kJ/mol	46.0254 ± 0.0010	56077-92-0*0
Difluorophosgene		-603.35	-606.45	± 0.41	kJ/mol	66.00691 ± 0.00085	353-50-4*0
Nitric acid		-124.50	-134.21	± 0.18	kJ/mol	63.01288 ± 0.00091	7697-37-2*0
Amidogen		188.91	186.02	± 0.11	kJ/mol	16.02262 ± 0.00016	13770-40-6*0
Allyl		180.03	168.30	± 0.45	kJ/mol	41.0718 ± 0.0024	1981-80-2*0
Iodide		-187.995	-188.396	± 0.0021	kJ/mol	126.905019 ± 0.000030	20461-54-5*0
Cyanogen chloride		134.95	135.65	± 0.46	kJ/mol	61.4701 ± 0.0012	506-77-4*0
iso-Butane		-106.03	-134.64	± 0.31	kJ/mol	58.1222 ± 0.0033	75-28-5*0
Isocyanic acid		-116.01	-119.00	± 0.30	kJ/mol	43.02478 ± 0.00086	75-13-8*0
Methylium		1099.336	1095.392	± 0.056	kJ/mol	15.03397 ± 0.00083	14531-53-4*0
Hypofluorous acid		-84.39	-87.29	± 0.19	kJ/mol	36.00574 ± 0.00031	14034-79-8*0
Hydrogen chloride			-166.452	± 0.024	kJ/mol	36.46064 ± 0.00090	7647-01-0*834
Ethoxide		-163.83	-178.77	± 0.47	kJ/mol	45.0610 ± 0.0017	16331-64-9*0
Propargyl		353.96	351.37	± 0.37	kJ/mol	39.0559 ± 0.0024	2932-78-7*0
Dichloromethane		-86.70	-93.56	± 0.52	kJ/mol	84.9320 ± 0.0020	75-09-2*0
Vinyl chloride		29.26	21.68	± 0.30	kJ/mol	62.4979 ± 0.0018	75-01-4*0
Chlorobenzene		67.14	52.18	± 0.61	kJ/mol	112.5566 ± 0.0049	108-90-7*0
Cyanogen bromide		186.7	180.1	± 1.1	kJ/mol	105.9214 ± 0.0013	506-68-3*0
Iodomethane		24.50	14.97	± 0.18	kJ/mol	141.93899 ± 0.00083	74-88-4*0
Hydroxyformyl		-181.09	-184.06	± 0.46	kJ/mol	45.0174 ± 0.0010	2564-86-5*1
Oxygen atom anion		105.868	108.097	± 0.0021	kJ/mol	15.99995 ± 0.00030	14337-01-0*0
Trihydrogen cation		1110.304	1106.696	± 0.013	kJ/mol	3.02327 ± 0.00021	28132-48-1*0
Methyl hydroperoxide		-114.94	-127.76	± 0.70	kJ/mol	48.0413 ± 0.0010	3031-73-0*0
Methylperoxy		22.30	12.66	± 0.47	kJ/mol	47.0333 ± 0.0010	2143-58-0*0
n-Propyl		118.30	100.90	± 0.55	kJ/mol	43.0877 ± 0.0024	2143-61-5*0
iso-Propyl		105.31	88.44	± 0.53	kJ/mol	43.0877 ± 0.0024	2025-55-0*0
2-Hydroxyethyl		-13.34	-26.60	± 0.56	kJ/mol	45.0605 ± 0.0017	4422-54-2*1
Tetrabromomethane		132.9	103.2	± 1.3	kJ/mol	331.6267 ± 0.0041	558-13-4*0
Difluoromethane		-443.08	-450.70	± 0.33	kJ/mol	52.02339 ± 0.00081	75-10-5*0
Cyanoacetylene		371.94	373.68	± 0.67	kJ/mol	51.0468 ± 0.0024	1070-71-9*0
Oxygen difluoride		26.81	24.56	± 0.24	kJ/mol	53.99621 ± 0.00030	7783-41-7*0
Hypochlorite		-118.60	-118.33	± 0.13	kJ/mol	51.45265 ± 0.00095	14380-61-1*0
Isocyanomethane		183.18	176.71	± 0.67	kJ/mol	41.0520 ± 0.0016	593-75-9*0
Propynylidene		543.41	546.40	± 0.64	kJ/mol	38.0480 ± 0.0024	67152-18-5*1
Ethenol		-112.77	-123.97	± 0.66	kJ/mol	44.0526 ± 0.0017	557-75-5*1
Chloroform		-97.29	-102.19	± 0.50	kJ/mol	119.3767 ± 0.0028	67-66-3*0
Fluoromethylidyne		243.14	246.74	± 0.13	kJ/mol	31.00910 ± 0.00080	3889-75-6*0
Acrylonitrile		193.84	187.08	± 0.71	kJ/mol	53.0627 ± 0.0024	107-13-1*1
Oxygen atom cation		1560.786	1562.644	± 0.0021	kJ/mol	15.99885 ± 0.00030	14581-93-2*0
1,2-Propadiene-1,3-diylidene		814.66	823.62	± 0.55	kJ/mol	36.0321 ± 0.0024	12075-35-3*0
Cyanic fluoride		8.78	9.11	± 0.69	kJ/mol	45.01584 ± 0.00080	1495-50-7*0
1-Hydroxyethyl		-42.74	-56.17	± 0.58	kJ/mol	45.0605 ± 0.0017	2348-46-1*1
Acetyl		-3.35	-10.01	± 0.34	kJ/mol	43.0446 ± 0.0016	3170-69-2*0
Formate		-463.20	-466.85	± 0.56	kJ/mol	45.0180 ± 0.0010	71-47-6*0
Methyl formate		-346.86	-359.91	± 0.84	kJ/mol	60.0520 ± 0.0017	107-31-3*1
Tetrafluoroethylene		-671.03	-674.43	± 0.54	kJ/mol	100.0150 ± 0.0016	116-14-3*0
Ethyl bromide		-41.38	-63.33	± 0.25	kJ/mol	108.9651 ± 0.0019	74-96-4*0
Vinyl bromide		88.57	73.76	± 0.58	kJ/mol	106.9492 ± 0.0019	593-60-2*0
Chlorine fluoride		-55.617	-55.712	± 0.055	kJ/mol	54.45110 ± 0.00090	7790-89-8*0
Hydride		143.264	145.228	± 0.000	kJ/mol	1.008489 ± 0.000070	12184-88-2*0
Diazynium		1042.43	1038.82	± 0.68	kJ/mol	29.02087 ± 0.00016	12357-66-3*0
Nitrite		-182.63	-185.44	± 0.46	kJ/mol	46.00609 ± 0.00060	14797-65-0*0
Hydroxylamine		-33.23	-43.61	± 0.46	kJ/mol	33.02996 ± 0.00037	7803-49-8*1
Nitrosyl hydride		109.93	106.96	± 0.11	kJ/mol	31.01408 ± 0.00032	14332-28-6*0
Nitrous acid		-73.008	-79.152	± 0.078	kJ/mol	47.01348 ± 0.00061	7782-77-6*1
Ethynylene		820.28	828.75	± 0.26	kJ/mol	24.0214 ± 0.0016	12070-15-4*0
Methanimine		96.48	88.57	± 0.42	kJ/mol	29.04126 ± 0.00083	2053-29-4*0
n-Butyl		102.73	80.22	± 0.70	kJ/mol	57.1143 ± 0.0033	2492-36-6*0
Cyclopentadiene		151.07	133.95	± 0.66	kJ/mol	66.1011 ± 0.0040	542-92-7*0
Methoxymethane		-166.46	-183.96	± 0.40	kJ/mol	46.0684 ± 0.0017	115-10-6*0
Methyl acetate		-394.29	-413.15	± 0.61	kJ/mol	74.0785 ± 0.0025	79-20-9*1
Phosgene		-217.45	-219.14	± 0.27	kJ/mol	98.9155 ± 0.0020	75-44-5*0
Chlorotrifluoromethane		-704.50	-709.61	± 0.59	kJ/mol	104.4586 ± 0.0012	75-72-9*0
Vinyl fluoride