Acetic anhydride
- Formula: C4H6O3
- Molecular weight: 102.0886
- IUPAC Standard InChIKey: WFDIJRYMOXRFFG-UHFFFAOYSA-N
- CAS Registry Number: 108-24-7
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Other names: Acetic acid, anhydride; Acetic oxide; Acetyl anhydride; Acetyl ether; Acetyl oxide; Ethanoic anhydride; (CH3CO)2O; Ethanoic anhydrate; Acetanhydride; Anhydride acetique; Anhydrid kyseliny octove; Anidride acetica; Azijnzuuranhydride; Essigsaeureanhydrid; Octowy bezwodnik; UN 1715; Acetyl acetate; Acetic acid, 1,1'-anhydride
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- Options:
Data at NIST subscription sites:
NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.
Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Glushko Thermocenter, Russian Academy of Sciences, Moscow
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
S°gas | 389.95 | J/mol*K | N/A | Stull D.R., 1969 |
Constant pressure heat capacity of gas
Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
99.50 | 298.15 | Stull D.R., 1969 | Selected values were based on an approximation of heat capacities from Cp(T) values of acetic acid. |
100.04 | 300. | ||
129.12 | 400. | ||
153.89 | 500. | ||
174.14 | 600. | ||
191.38 | 700. | ||
204.64 | 800. | ||
216.06 | 900. | ||
226.40 | 1000. |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°liquid | -625.0 ± 3.4 | kJ/mol | Cm | Guthrie, 1974 | Reanalyzed by Pedley, Naylor, et al., 1986, Original value = -628.4 ± 3.3 kJ/mol; Heat of hydrolysis[kcal/mol]=-40.6±0.80; ALS |
Constant pressure heat capacity of liquid
Cp,liquid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
168.2 | 303.2 | Phillip, 1939 | DH |
Phase change data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 412. ± 5. | K | AVG | N/A | Average of 10 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 200. ± 1. | K | AVG | N/A | Average of 8 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 606. | K | N/A | Ambrose and Ghiassee, 1987 | Uncertainty assigned by TRC = 4. K; decomposition of sample prevented accurate measurement, reported value based partly on a correlation; TRC |
Tc | 569. | K | N/A | Vespigniani, 1903 | Uncertainty assigned by TRC = 20. K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 40.00 | bar | N/A | Ambrose and Ghiassee, 1987 | Uncertainty assigned by TRC = 2.00 bar; based partly on a corelation because of decompostion of smp.; TRC |
Pc | 46.80 | bar | N/A | Vespigniani, 1903 | Uncertainty assigned by TRC = 4.053 bar; TRC |
Reduced pressure boiling point
Tboil (K) | Pressure (bar) | Reference | Comment |
---|---|---|---|
317.2 | 0.020 | Weast and Grasselli, 1989 | BS |
317. | 0.020 | Buckingham and Donaghy, 1982 | BS |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
43.3 | 364. | EB | Ambrose and Ghiassee, 1987, 2 | Based on data from 349. to 429. K.; AC |
47.6 | 428. | A | Stephenson and Malanowski, 1987 | Based on data from 413. to 526. K.; AC |
45.5 | 335. | A | Stephenson and Malanowski, 1987 | Based on data from 320. to 413. K. See also Dykyj, 1971.; AC |
44.2 | 351. | N/A | McDonald, Shrader, et al., 1959 | Based on data from 336. to 412. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A | B | C | Reference |
---|---|---|---|---|
335.99 to 412.57 | 4.24655 | 1427.77 | -75.113 | McDonald, Shrader, et al., 1959 |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
RCD - Robert C. Dunbar
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
By formula: C4H6O3 + H2O = 2C2H4O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -56.6 ± 4.0 | kJ/mol | Cm | Becker and Maelicke, 1967 | liquid phase; ALS |
ΔrH° | -58.6 ± 0.4 | kJ/mol | Cm | Wadso, 1962 | liquid phase; ALS |
ΔrH° | -58.4 ± 0.4 | kJ/mol | Cm | Conn, Kistiakowsky, et al., 1942 | liquid phase; Heat of hydrolysis at 303 K; ALS |
By formula: C4H6O3 + C4H11N = C6H13NO + C2H4O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -113.2 ± 0.46 | kJ/mol | Cm | Wadso, 1962 | liquid phase; ALS |
ΔrH° | -163.7 ± 0.3 | kJ/mol | Cm | Wadso, 1958 | liquid phase; Heat of aminolysis; ALS |
By formula: Na+ + C4H6O3 = (Na+ • C4H6O3)
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
130. | 298. | IMRE | McMahon and Ohanessian, 2000 | Anchor alanine=39.89; RCD |
By formula: C4H6O3 + 2C3H6O3 = C6H10O5 + 2C2H4O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 0.0 | kJ/mol | Eqk | Utkin, Bogel'fer, et al., 1991 | liquid phase; NMR; ALS |
By formula: 2C2H4O2 = C4H6O3 + H2O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 63.7 ± 1.2 | kJ/mol | Eqk | Knopp, Linnell, et al., 1962 | liquid phase; ALS |
By formula: C4H6O3 + C6H7N = C8H9NO + C2H4O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -100.9 ± 0.3 | kJ/mol | Cm | Wadso, 1962 | liquid phase; ALS |
By formula: C2H3NO4 + C2H4O2 = C4H6O3 + HNO3
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 16.7 | kJ/mol | Cm | Tsvetkov, Shmakov, et al., 1989 | liquid phase; ALS |
By formula: C4H6O3 + C9H13N3O5 = C11H15N3O6 + C2H4O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -43.9 | kJ/mol | Kin | Shatynski and Hanesian, 1993 | solid phase; ALS |
By formula: C2H2O + C2H4O2 = C4H6O3
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -87.5 ± 2.2 | kJ/mol | Eqk | Blake, Davies, et al., 1971 | gas phase; ALS |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Ion clustering data, Mass spectrum (electron ionization), Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
View reactions leading to C4H6O3+ (ion structure unspecified)
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
~10.0 | PE | Bock, Hirabayashi, et al., 1981 | LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C2H3O+ | 10.14 | CH3COO | PI | Traeger, McLouglin, et al., 1982 | LBLHLM |
C2H3O+ | 10.19 ± 0.02 | ? | PI | Shigorin, Filyugina, et al., 1967 | RDSH |
C2H4O2+ | 9.65 ± 0.02 | CH2=CO? | PI | Shigorin, Filyugina, et al., 1967 | RDSH |
C3H3O3+ | 10.14 ± 0.02 | CH3 | PI | Shigorin, Filyugina, et al., 1967 | RDSH |
Ion clustering data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Robert C. Dunbar
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.
Clustering reactions
By formula: Na+ + C4H6O3 = (Na+ • C4H6O3)
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
130. | 298. | IMRE | McMahon and Ohanessian, 2000 | Anchor alanine=39.89 |
Mass spectrum (electron ionization)
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.
Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | NIST Mass Spectrometry Data Center, 1998. |
NIST MS number | 291302 |
Gas Chromatography
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Normal alkane RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | OV-101 | 706. | Zenkevich, 2005 | 25. m/0.20 mm/0.10 μm, N2/He, 6. K/min; Tstart: 50. C; Tend: 250. C |
Normal alkane RI, non-polar column, custom temperature program
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | Polydimethyl siloxanes | 706. | Zenkevich, 2001 | Program: not specified |
Capillary | Methyl Silicone | 699. | Zenkevich, Korolenko, et al., 1995 | Program: not specified |
Normal alkane RI, polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | DB-Wax | 1236. | Umano, Hagi, et al., 1995 | He, 40. C @ 2. min, 2. K/min; Column length: 60. m; Column diameter: 0.25 mm; Tend: 200. C |
Capillary | Carbowax 20M | 1240. | Kawakami, Kobayashi, et al., 1993 | He, 60. C @ 4. min, 2. K/min; Column length: 50. m; Column diameter: 0.25 mm; Tend: 180. C |
Normal alkane RI, polar column, custom temperature program
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | Polyethylene Glycol | 1227. | Zenkevich, Korolenko, et al., 1995 | Program: not specified |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Gas Chromatography, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Stull D.R., 1969
Stull D.R., Jr.,
The Chemical Thermodynamics of Organic Compounds. Wiley, New York, 1969. [all data]
Guthrie, 1974
Guthrie, J.P.,
Hydration of carboxamides. Evaluation of the free energy change for addition of water to acetamide and formamide derivatives,
J. Am. Chem. Soc., 1974, 96, 3608-3615. [all data]
Pedley, Naylor, et al., 1986
Pedley, J.B.; Naylor, R.D.; Kirby, S.P.,
Thermochemical Data of Organic Compounds, Chapman and Hall, New York, 1986, 1-792. [all data]
Phillip, 1939
Phillip, N.M.,
Adiabatic and isothermal compressibilities of liquids,
Proc. Indian Acad. Sci., 1939, A9, 109-120. [all data]
Ambrose and Ghiassee, 1987
Ambrose, D.; Ghiassee, N.B.,
Vapor Pressure, Critical Temperature and Critical Pressure of Acetic Anhydride,
J. Chem. Thermodyn., 1987, 19, 911. [all data]
Vespigniani, 1903
Vespigniani, G.R.,
Gazz. Chim. Ital., 1903, 33, 73-8. [all data]
Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]
Buckingham and Donaghy, 1982
Buckingham, J.; Donaghy, S.M.,
Dictionary of Organic Compounds: Fifth Edition, Chapman and Hall, New York, 1982, 1. [all data]
Ambrose and Ghiassee, 1987, 2
Ambrose, D.; Ghiassee, N.B.,
Vapour pressure, critical temperature, and critical pressure of acetic anhydride,
The Journal of Chemical Thermodynamics, 1987, 19, 9, 911-913, https://doi.org/10.1016/0021-9614(87)90037-1
. [all data]
Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw,
Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2
. [all data]
Dykyj, 1971
Dykyj, J.,
Petrochemia, 1971, 11, 2, 27. [all data]
McDonald, Shrader, et al., 1959
McDonald, R.A.; Shrader, S.A.; Stull, D.R.,
Vapor Pressures and Freezing Points of Thirty Pure Organic Compounds.,
J. Chem. Eng. Data, 1959, 4, 4, 311-313, https://doi.org/10.1021/je60004a009
. [all data]
Becker and Maelicke, 1967
Becker, F.; Maelicke, A.,
Thermokinetische Messungen nach dem Prinzip der Wärmefluβkalorimetrie,
Z. Phys. Chem. (Neue Folge), 1967, 55, 280-295. [all data]
Wadso, 1962
Wadso, I.,
Heats of aminolysis and hydrolysis of some N-acetyl compounds and of acetic anhydride,
Acta Chem. Scand., 1962, 16, 471-478. [all data]
Conn, Kistiakowsky, et al., 1942
Conn, J.B.; Kistiakowsky, G.B.; Roberts, R.M.; Smith, E.A.,
Heats of organic reactions. XIII. Heats of hydrolysis of some acid anhydrides,
J. Am. Chem. Soc., 1942, 64, 1747-17. [all data]
Wadso, 1958
Wadso, I.,
The heats of aminolysis of n-butyl thiolacetate and acetic anhydride,
Acta Chem. Scand., 1958, 12, 635-640. [all data]
McMahon and Ohanessian, 2000
McMahon, T.B.; Ohanessian, G.,
An Experimental and Ab Initio Study of the Nature of the Binding in Gas-Phase Complexes of Sodium Ions,
Chem. Eur. J., 2000, 6, 16, 2931, https://doi.org/10.1002/1521-3765(20000818)6:16<2931::AID-CHEM2931>3.0.CO;2-7
. [all data]
Utkin, Bogel'fer, et al., 1991
Utkin, A.Yu.; Bogel'fer, L.Ya.; Chimishkyan, A.L.,
Reversible reactions in the acidolysis of methyoxyacetic acid by acetic anhydride,
Russ. J. Phys. Chem. (Engl. Transl.), 1991, 65, 1049-1059, In original 1974. [all data]
Knopp, Linnell, et al., 1962
Knopp, J.A.; Linnell, W.S.; Child, W.C., Jr.,
The thermodynamics of the thermal decomposition of acetic acid in the liquid phase,
J. Phys. Chem., 1962, 66, 1513-1516. [all data]
Tsvetkov, Shmakov, et al., 1989
Tsvetkov, V.G.; Shmakov, V.A.; Sopin, V.F.; Ivanov, A.V.; Ikonnikov, A.A.; Marchenko, G.N.,
Enthalpies of reaction of nitric acid with acetic and trifluoroacetic anhydrides,
J. Gen. Chem. USSR, 1989, 59, 1220-1222. [all data]
Shatynski and Hanesian, 1993
Shatynski, J.J.; Hanesian, D.,
Adiabatic kinetic studies of the cytidine/acetic anhydride reaction by utilizing temperature versus time data,
Ind. Eng. Chem. Res., 1993, 32, 594-599. [all data]
Blake, Davies, et al., 1971
Blake, P.G.; Davies, H.H.; Speis, A.,
Reactions of keten. Part II. The thermodynamics of the gas-phase equilibrium: acetic acid + keten = acetic anhydride,
J. Chem. Soc. B, 1971, 2050-2052. [all data]
Bock, Hirabayashi, et al., 1981
Bock, H.; Hirabayashi, T.; Mohmand, S.,
Thermische erzeugung von alkyl- und halogenketenen,
Chem. Ber., 1981, 114, 2595. [all data]
Traeger, McLouglin, et al., 1982
Traeger, J.C.; McLouglin, R.G.; Nicholson, A.J.C.,
Heat of formation for acetyl cation in the gas phase,
J. Am. Chem. Soc., 1982, 104, 5318. [all data]
Shigorin, Filyugina, et al., 1967
Shigorin, D.N.; Filyugina, A.D.; Potapov, V.K.,
Role of intramolecular hydrogen bonding in the ionisation and dissociation of compounds,
Zh. Fiz. Khim., 1967, 41, 2336, In original 1255. [all data]
Zenkevich, 2005
Zenkevich, I.G.,
Experimentally measured retention indices., 2005. [all data]
Zenkevich, 2001
Zenkevich, I.G.,
Encyclopedia of Chromatography. Derivatization of Amines, Amino Acids, Amides and Imides for GC Analysis, Marcel Dekker, Inc, New York - Basel, 2001, 224. [all data]
Zenkevich, Korolenko, et al., 1995
Zenkevich, I.G.; Korolenko, L.I.; Khralenkova, N.B.,
Desorption with solvent vapor as a method of sample preparation in the sorption preconcentration of organic-compounds from the air of a working area and from industrial-waste gases,
J. Appl. Chem. USSR (Engl. Transl.), 1995, 50, 10, 937-944. [all data]
Umano, Hagi, et al., 1995
Umano, K.; Hagi, Y.; Nakahara, K.; Shyoji, A.; Shibamoto, T.,
Volatile chemicals formed in the headspace of a heated D-glucose/L-cysteine Maillard model system,
J. Agric. Food Chem., 1995, 43, 8, 2212-2218, https://doi.org/10.1021/jf00056a046
. [all data]
Kawakami, Kobayashi, et al., 1993
Kawakami, M.; Kobayashi, A.; Kator, K.,
Volatile constituents of Rooibos tea (Aspalathus linearis) as affected by extraction process,
J. Agric. Food Chem., 1993, 41, 4, 633-636, https://doi.org/10.1021/jf00028a023
. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Gas Chromatography, References
- Symbols used in this document:
AE Appearance energy Cp,gas Constant pressure heat capacity of gas Cp,liquid Constant pressure heat capacity of liquid Pc Critical pressure S°gas Entropy of gas at standard conditions T Temperature Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH Enthalpy of vaporization - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (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 judgment. 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.
- Customer support for NIST Standard Reference Data products.