hydrogen fluoride
- Formula: FH
- Molecular weight: 20.00634
- IUPAC Standard InChIKey: KRHYYFGTRYWZRS-UHFFFAOYSA-N
- CAS Registry Number: 7664-39-3
- 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. - Isotopologues:
- 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, Phase change data, Constants of diatomic molecules, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -273.30 ± 0.70 | kJ/mol | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
ΔfH°gas | -272.55 | kJ/mol | Review | Chase, 1998 | Data last reviewed in June, 1977 |
Quantity | Value | Units | Method | Reference | Comment |
S°gas,1 bar | 173.779 ± 0.003 | J/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
S°gas,1 bar | 173.78 | J/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1977 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = A + B*t + C*t2 + D*t3 +
E/t2
H° − H°298.15= A*t + B*t2/2 +
C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 −
E/(2*t2) + G
Cp = heat capacity (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | 298. to 1000. | 1000. to 6000. |
---|---|---|
A | 30.11693 | 24.57033 |
B | -3.246612 | 6.893391 |
C | 2.868116 | -1.243874 |
D | 0.457914 | 0.082583 |
E | -0.024861 | -0.234060 |
F | -281.4912 | -279.7653 |
G | 210.9226 | 202.8525 |
H | -272.5462 | -272.5462 |
Reference | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in June, 1977 | Data last reviewed in June, 1977 |
Phase change data
Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, 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:
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 | 292.7 | K | N/A | Streng, 1971 | Uncertainty assigned by TRC = 0.25 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 190. | K | N/A | Streng, 1971 | Uncertainty assigned by TRC = 0.2 K; TRC |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
25.2 | 265. | Campbell and Campbell, 1934 | Based on data from 240. to 290. K.; AC |
25.2 | 255. | Simons, 1924 | Based on data from 190. to 320. 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 | Comment |
---|---|---|---|---|---|
273.17 to 303.09 | 4.9148 | 1556.559 | 24.199 | Sheft, Perkins, et al., 1973 | Coefficents calculated by NIST from author's data. |
198.5 to 292.9 | 4.16129 | 1142.985 | -17.993 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
Constants of diatomic molecules
Go To: Top, Gas phase thermochemistry data, Phase change data, 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: Klaus P. Huber and Gerhard H. Herzberg
Data collected through January, 1977
Symbol | Meaning |
---|---|
State | electronic state and / or symmetry symbol |
Te | minimum electronic energy (cm-1) |
ωe | vibrational constant – first term (cm-1) |
ωexe | vibrational constant – second term (cm-1) |
ωeye | vibrational constant – third term (cm-1) |
Be | rotational constant in equilibrium position (cm-1) |
αe | rotational constant – first term (cm-1) |
γe | rotation-vibration interaction constant (cm-1) |
De | centrifugal distortion constant (cm-1) |
βe | rotational constant – first term, centrifugal force (cm-1) |
re | internuclear distance (Å) |
Trans. | observed transition(s) corresponding to electronic state |
ν00 | position of 0-0 band (units noted in table) |
State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Rydberg 1 | Rydberg levels converging to the ground state of HF+ have been observed in the electronic energy loss spectrum. | |||||||||||
D 1Σ+ 1 | D ← X | |||||||||||
↳di Londardo and Douglas, 1973 | ||||||||||||
C 1Π | (105820) | [2636] | [16.0] | [1.049] | C ← X R | 105090.8 | ||||||
↳di Lonardo and Douglas, 1972; di Londardo and Douglas, 1973 | ||||||||||||
b 3Π 2 | b ← X | |||||||||||
↳di Lonardo and Douglas, 1972 | ||||||||||||
State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
B 1Σ+ | 84776.65 | 1159.18 Z | 18.005 3 | 0.184 | 4.0291 4 | 0.0177 5 | 1.932E-4 6 | 2.09086 | B ↔ X 7 R | 83304.96 Z | ||
↳Johns and Barrow, 1959; missing citation | ||||||||||||
A | Continuous absorption starting at 60600 cm-1. 8 | |||||||||||
↳Safari, 1954 | ||||||||||||
X 1Σ+ | 0 | 4138.32 9 Z | 89.88 10 | 20.9557 9 11 12 | 0.798 13 | 21.51E-4 14 | 0.916808 15 | |||||
↳Mann, Thrush, et al., 1961; Herget, Deeds, et al., 1962; Fishburne and Rao, 1966; Webb and Rao, 1968 | ||||||||||||
Rotation sp. 16 17 | ||||||||||||
↳Rothschild, 1964; Revich and Stankevich, 1966; Mason and Nielsen, 1967 | ||||||||||||
Mol. Beam el. Reson. 18 | ||||||||||||
↳Weiss, 1963; Muenter and Klemperer, 1970; Muenter, 1972; de Leeuw and Dymanus, 1973 | ||||||||||||
Mol. Beam magn. Reson. 19 | ||||||||||||
↳Baker, Nelson, et al., 1961 |
Notes
1 | Two strong bands between 104000 and 116000 cm-1, not yet analysed. |
2 | Absorption bands above 100000 cm-1, not yet analysed. |
3 | The vibrational and rotational constants, were obtained from a fit to the seven lowest vibrational levels di Londardo and Douglas, 1973. See 7. |
4 | RKR potential curves Fallon, Vanderslice, et al., 1960, di Londardo and Douglas, 1973. |
5 | -0.000950(v+1/2)2 + 0.000060l(v+1/2)3; see 3. |
6 | +0.182E-4(v+1/2) + 0.00551E-4(v+1/2)2; see 3. |
7 | Very extensive band system (also called V-X) extending in absorption from 96000 to 117000, in emission from 36000 to 70000 cm-1. Strong perturbations above v'=27, but bands have been identified to v'=73. The B (or V) state was also observed in the electron energy loss spectrum Salama and Hasted, 1976. |
8 | HF is quite transparent to 1650 Safari, 1954. Theoretical potential curves for three repulsive states (3Π, 1Π, 3Σ+) arising from ground state atomic products were given by Dunning, 1976. |
9 | Introduction of the Dunham correction Webb and Rao, 1968 gives ωe = 4138.767 Webb and Rao, 1968 and Be = 20.9561. |
10 | +0.90(v+1/2)3 - 0.0ll0(v+1/2)4 - 0.00067(v+1/2)5, v≤9 Webb and Rao, 1968. A different formula for higher vibrational levels (v≤19) was derived by Johns and Barrow, 1959. All levels up to the last (v=19) are tabulated in di Londardo and Douglas, 1973). |
11 | For v=14,...19 the rotational levels break off at decreasing J on account of predissociation by rotation. A few broadened lines near these limits have been observed di Londardo and Douglas, 1973. From the limiting curve the dissociation energy 47333 ± 60 cm-1 has been determined di Londardo and Douglas, 1973. |
12 | RKR potential curves Fallon, Vanderslice, et al., 1960, di Londardo and Douglas, 1973, Dunham potential coefficients Webb and Rao, 1968, Ogilvie and Koo, 1976. Ab initio calculations of molecular constants Bondybey, Pearson, et al., 1972, Krauss and Neumann, 1974, Meyer and Rosmus, 1975, Dunning, 1976. |
13 | +0.0127(v+1/2)2 - 0.00044(v+1/2)3 , from Webb and Rao, 1968. |
14 | -0.68E-4(v+1/2)+0.029E-4(v+1/2)2, He = 1.59E-7; from Webb and Rao, 1968; see also Mann, Thrush, et al., 1961. |
15 | Rot.-vibr. Sp. 22 23 17 |
16 | Laser emission in the pure rotation spectrum Deutsch, 1967. |
17 | Rotation and rotation-vibration spectra in rare-gas matrices Mason, von Holle, et al., 1971. |
18 | μel(v=0,J=1) = 1.82618 D Muenter and Klemperer, 1970, Muenter, 1972; gJ = 0.7410, quadrupole moment Θm= 2.36E-26 esu cm2 de Leeuw and Dymanus, 1973; also nuclear spin - rotation and other hyperfine structure constants. |
19 | Nuclear reorientation spectrum. |
20 | From the limiting curve of dissociation for the ground state di Londardo and Douglas, 1973; see 11. |
21 | From photoelectron spectra Walker, Dehmer, et al., 1973, Guyon, Spohr, et al., 1976. Earlier photoionization studies yielded 16.007 eV Berkowitz, Chupka, et al., 1971, a value strongly affected by the presence of autoionizing Rydberg levels in the threshold region Guyon, Spohr, et al., 1976. The second ionization potential (removal of a 3σ electron) from the photoelectron spectrum Berkowitz, 1971, Guyon, Spohr, et al., 1976 is 19.118 eV in agreement with the value derived from the spectrum of HF+. The third and fourth ionization potentials (removal of a 2σ and 1σ electron, respectively) are 39.61 Banna and Shirley, 1975, Shaw and Thomas, 1975 and 694.25 eV Shaw and Thomas, 1975; these are vertical potentials from X-ray photoelectron spectra. |
22 | 1-0, 2-0 bands studied in absorption under high resolution by Herget, Deeds, et al., 1962, Webb and Rao, 1968, 3-0, 4-0, 5-0 in the photographic infrared by Naude and Verleger, 1950, Fishburne and Rao, 1966. In emission, rotation-vibration bands have been studied by Mann, Thrush, et al., 1961 and Sileo and Cool, 1976, the latter extending the chemical laser emission, first observed in the 2-1 band by Kompa and Pimentel, 1967, to v=9 and Δv=6. Electric discharge induced laser emission in the 3-2, 2-1, 1-0 bands, see Deutsch, 1967, 2, Coldhar, Osgood, et al., 1971. |
23 | Line strengths, collision-broadened widths, dipole moment function Meredith, 1972, Spellicy, Meredith, et al., 1972, Lie, 1974, Rimpel, 1974, Sileo and Cool, 1976, Yardley and Balint-Kurti, 1976. The radiative lifetime of v=1 [P(4) line] is 6.16 ms Hinchen, 1974. Sileo and Cool, 1976 give a vibrational dipole moment matrix for v ≤ 9 based on intensity measurements in chemical laser emission. |
References
Go To: Top, Gas phase thermochemistry data, Phase change data, Constants of diatomic molecules, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A.,
CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]
Chase, 1998
Chase, M.W., Jr.,
NIST-JANAF Themochemical Tables, Fourth Edition,
J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]
Streng, 1971
Streng, A.G.,
Miscibility and Compatibility of Some Liquid and Solidified Gases at Low Temperature,
J. Chem. Eng. Data, 1971, 16, 357. [all data]
Campbell and Campbell, 1934
Campbell, Alan Newton; Campbell, Alexandra Jean Robson,
The thermodynamics of binary liquid mixtures : formic acid and water,
Trans. Faraday Soc., 1934, 30, 1109, https://doi.org/10.1039/tf9343001109
. [all data]
Simons, 1924
Simons, Joseph,
THE PREPARATION, FREEZING POINT AND VAPOR PRESSURE OF HYDROGEN FLUORIDE,
J. Am. Chem. Soc., 1924, 46, 10, 2179-2183, https://doi.org/10.1021/ja01675a006
. [all data]
Sheft, Perkins, et al., 1973
Sheft, I.; Perkins, A.J.; Hyman, H.H.,
Anhydrous Hydrogen Fluoride: Vapor Pressure and Liquid Density,
J. Inorg. Nucl. Chem., 1973, 35, 11, 3677-3680, https://doi.org/10.1016/0022-1902(73)80055-7
. [all data]
Stull, 1947
Stull, Daniel R.,
Vapor Pressure of Pure Substances. Organic and Inorganic Compounds,
Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022
. [all data]
di Londardo and Douglas, 1973
di Londardo, G.; Douglas, A.E.,
The electronic spectrum of HF. I. The B1Σ+-X1Σ+ 1 band system,
Can. J. Phys., 1973, 51, 434. [all data]
di Lonardo and Douglas, 1972
di Lonardo, G.; Douglas, A.E.,
Electronic spectra of HF and F2,
J. Chem. Phys., 1972, 56, 5185. [all data]
Johns and Barrow, 1959
Johns, J.W.C.; Barrow, R.F.,
The ultra-violet spectra of HF and DF,
Proc. R. Soc. London A, 1959, 251, 504. [all data]
Safari, 1954
Safari, E.,
Contribution a l'etude spectrale de l'acide fluorhydrique,
Ann. Phys. (Paris), 1954, 9, 203. [all data]
Mann, Thrush, et al., 1961
Mann, D.E.; Thrush, B.A.; Lide, D.R., Jr.; Ball, J.J.; Acquista, N.,
Spectroscopy of fluorine flames. I. Hydrogen-fluorine flame and the vibration-rotation emission spectrum of HF,
J. Chem. Phys., 1961, 34, 420. [all data]
Herget, Deeds, et al., 1962
Herget, W.F.; Deeds, W.E.; Gailar, N.M.; Lovell, R.J.; Nielsen, A.H.,
Infrared spectrum of hydrogen fluoride: line positions and line shapes. Part II. Treatment of data and results,
J. Opt. Soc. Am., 1962, 52, 1113. [all data]
Fishburne and Rao, 1966
Fishburne, E.S.; Rao, K.N.,
Vibration rotation bands of HF,
J. Mol. Spectrosc., 1966, 19, 290. [all data]
Webb and Rao, 1968
Webb, D.U.; Rao, K.N.,
Vibration rotation bands of heated hydrogen halides,
J. Mol. Spectrosc., 1968, 28, 121. [all data]
Rothschild, 1964
Rothschild, W.G.,
Pure rotational absorption spectrum of hydrogen fluoride vapor between 22 and 250 μ,
J. Opt. Soc. Am., 1964, 54, 20. [all data]
Revich and Stankevich, 1966
Revich, V.E.; Stankevich, S.A.,
The rotational spectra of HF and DF molecules,
Dokl. Phys. Chem. Engl. Transl., 1966, 170, 699, In original 1376. [all data]
Mason and Nielsen, 1967
Mason, A.A.; Nielsen, A.H.,
Rotational spectrum of hydrogen fluoride: frequencies and linewidths,
J. Opt. Soc. Am., 1967, 57, 1464. [all data]
Weiss, 1963
Weiss, R.,
Stark effect and hyperfine structure of hydrogen fluoride,
Phys. Rev., 1963, 131, 659. [all data]
Muenter and Klemperer, 1970
Muenter, J.S.; Klemperer, W.,
Hyperfine structure constants of HF and DF,
J. Chem. Phys., 1970, 52, 6033. [all data]
Muenter, 1972
Muenter, J.S.,
Polarizability anisotropy of hydrogen fluoride,
J. Chem. Phys., 1972, 56, 5409. [all data]
de Leeuw and Dymanus, 1973
de Leeuw, F.H.; Dymanus, A.,
Magnetic properties and molecular quadrupole moment of HF and HCl by molecular-beam electric-resonance spectroscopy,
J. Mol. Spectrosc., 1973, 48, 427. [all data]
Baker, Nelson, et al., 1961
Baker, M.R.; Nelson, H.M.; Leavitt, J.A.; Ramsey, N.F.,
Nuclear magnetic interactions in hydrogen fluoride,
Phys. Rev., 1961, 121, 807. [all data]
Fallon, Vanderslice, et al., 1960
Fallon, R.J.; Vanderslice, J.T.; Mason, E.A.,
Potential energy curves of hydrogen fluoride,
J. Chem. Phys., 1960, 32, 698. [all data]
Salama and Hasted, 1976
Salama, A.; Hasted, J.B.,
Electron energy loss spectrum of hydrogen fluoride,
J. Phys. B:, 1976, 9, 333. [all data]
Dunning, 1976
Dunning, T.H., Jr.,
The low-lying states of hydrogen fluoride: potential energy curves for the X1Σ+, 3Σ+, 3Π, and 1Π states,
J. Chem. Phys., 1976, 65, 3854. [all data]
Ogilvie and Koo, 1976
Ogilvie, J.F.; Koo, D.,
Dunham potential energy coefficients of the hydrogen halides and carbon monoxide,
J. Mol. Spectrosc., 1976, 61, 332-336. [all data]
Bondybey, Pearson, et al., 1972
Bondybey, V.; Pearson, P.K.; Schaefer, H.F., III,
Theoretical potential energy curves for OH, HF+, HF, HF-, NeH+, and NeH,
J. Chem. Phys., 1972, 57, 1123. [all data]
Krauss and Neumann, 1974
Krauss, M.; Neumann, D.,
Multi-configuration self-consistent-field calculation of the dissociation energy and electronic structure of hydrogen fluoride,
Mol. Phys., 1974, 27, 917. [all data]
Meyer and Rosmus, 1975
Meyer, W.; Rosmus, P.,
PNO-Cl and CEPA studies of electron correlation effects. III. Spectroscopic constants and dipole moment functions for the ground states of the first-row and second-row diatomic hydrides,
J. Chem. Phys., 1975, 63, 2356. [all data]
Deutsch, 1967
Deutsch, T.F.,
Laser emission from HF rotational transitions,
Appl. Phys. Lett., 1967, 11, 18. [all data]
Mason, von Holle, et al., 1971
Mason, M.G.; von Holle, W.G.; Robinson, D.W.,
Mid- and far-infrared spectra of HF and DF in rare-gas matrices,
J. Chem. Phys., 1971, 54, 3491. [all data]
Walker, Dehmer, et al., 1973
Walker, T.E.H.; Dehmer, P.M.; Berkowitz, J.,
Rotational band shapes in photoelectron spectroscopy: HF DF,
J. Chem. Phys., 1973, 59, 4292. [all data]
Guyon, Spohr, et al., 1976
Guyon, P.-M.; Spohr, R.; Chupka, W.A.; Berkowitz, J.,
Threshold photoelectron spectra of HF, DF, and F2,
J. Chem. Phys., 1976, 65, 1650-1658. [all data]
Berkowitz, Chupka, et al., 1971
Berkowitz, J.; Chupka, W.A.; Guyon, P.M.; Holloway, J.H.; Spohr, R.,
Photoionization mass spectrometric study of F2, HF, and DF,
J. Chem. Phys., 1971, 54, 5165. [all data]
Berkowitz, 1971
Berkowitz, J.,
Experimental potential energy curves for X2{PI} and 2Σ+ states of HF+,
Chem. Phys. Lett., 1971, 11, 21. [all data]
Banna and Shirley, 1975
Banna, M.S.; Shirley, D.A.,
Molecular photoelectron spectroscopy at 132.3 eV. The second-row hydrides,
J. Chem. Phys., 1975, 63, 4759. [all data]
Shaw and Thomas, 1975
Shaw, R.W., Jr.; Thomas, T.D.,
Auger electron spectrum and ionization potentials of the HF molecule,
Phys. Rev. A:, 1975, 11, 1491. [all data]
Naude and Verleger, 1950
Naude, S.M.; Verleger, H.,
The vibration-rotation bands of the hydrogen halides HF, H35Cl, H37Cl, H79Br, H81Br and H127I,
Proc. Phys. Soc. London Sect. A, 1950, 63, 470. [all data]
Sileo and Cool, 1976
Sileo, R.N.; Cool, T.A.,
Overtone emission spectroscopy of HF and DF: vibrational matrix elements and dipole moment function,
J. Chem. Phys., 1976, 65, 117. [all data]
Kompa and Pimentel, 1967
Kompa, K.L.; Pimentel, G.C.,
Hydrofluoric acid chemical laser,
J. Chem. Phys., 1967, 47, 857. [all data]
Deutsch, 1967, 2
Deutsch, T.F.,
Molecular laser action in hydrogen and deuterium halides,
Appl. Phys. Lett., 1967, 10, 234. [all data]
Coldhar, Osgood, et al., 1971
Coldhar, J.; Osgood, R.M., Jr.; Javan, A.,
Observation of intense superradiant emission in the high-gain infrared transitions of HF and DF molecules,
Appl. Phys. Lett., 1971, 18, 167. [all data]
Meredith, 1972
Meredith, R.E.,
Strengths and widths in the first overtone band of hydrogen fluoride,
J. Quant. Spectrosc. Radiat. Transfer, 1972, 12, 485. [all data]
Spellicy, Meredith, et al., 1972
Spellicy, R.L.; Meredith, R.E.; Smith, F.G.,
Strengths and collision broadened widths in the second overtone band of hydrogen fluoride,
J. Chem. Phys., 1972, 57, 5119. [all data]
Lie, 1974
Lie, G.C.,
Study of the theoretical dipole moment function and infrared transition matrix for the X1Σ+ state of the HF molecule,
J. Chem. Phys., 1974, 60, 2991. [all data]
Rimpel, 1974
Rimpel, G.,
Linienstarken in der 4-0- und 5-0-Rotationsschwingungsbande von Fluorwasserstoff,
Z. Naturforsch. A, 1974, 29, 588. [all data]
Yardley and Balint-Kurti, 1976
Yardley, R.N.; Balint-Kurti, G.G.,
Ab initio valence-bond calculations on HF, LiH, LiH+ and LiF,
Mol. Phys., 1976, 31, 921. [all data]
Hinchen, 1974
Hinchen, J.J.,
Determination of vibration-rotation line strengths for HF and DF by use of an HF/DF cw laser,
J. Opt. Soc. Am., 1974, 64, 1162. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, Constants of diatomic molecules, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) Tboil Boiling point Tfus Fusion (melting) point ΔfH°gas Enthalpy of formation of gas 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.