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Experimental data for H2O (Water)

16 09 12 13 50
Other names
Dihydrogen oxide; Distilled water; Ice; Water vapor; Water; oxidane;
INChI INChIKey SMILES IUPAC name
InChI=1S/H2O/h1H2 XLYOFNOQVPJJNP-UHFFFAOYSA-N O oxidane
State Conformation
1A1 C2V
Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)
Property Value Uncertainty units Reference Comment
Hfg(298.15K) enthalpy of formation -241.81 0.03 kJ mol-1 2006Rus/Pin:6592
Hfg(0K) enthalpy of formation -238.90 0.03 kJ mol-1 2006Rus/Pin:6592
Entropy (298.15K) entropy 188.84 0.01 J K-1 mol-1 CODATA
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 9.90 0.00 kJ mol-1 CODATA
Heat Capacity (298.15K) heat capacity 33.60   J K-1 mol-1 CODATA
Information can also be found for this species in the NIST Chemistry Webbook
Vibrational levels (cm-1) vibrations
Mode Number Symmetry Frequency (cm-1) Frequency Reference Intensity (km mol-1) Int. unc. Intensity Reference Comment
1 A1 3657 Shim 2.9   1992Cul/Lie:502
2 A1 1595 Shim 62.5   1992Cul/Lie:502
3 B2 3756 1979HUB/HER 41.7    

vibrational zero-point energy: 4504.0 cm-1
Calculated vibrational frequencies for H2O (Water).
Gas-phase IR spectra can be found in the NIST Chemistry Webbook here.
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
27.87700 14.51200 9.28500 1966Herzberg

Calculated rotational constants for H2O (Water).
Product of moments of inertia moments of inertia
1.275365amu3Å6   5.83985896432972E-120gm3 cm6
Geometric Data
picture of Water

Point Group C2v


Internal coordinates
distances (r) in Å, angles (a) in degrees, dihedrals (d) in degrees
Description Value unc. Connectivity Reference Comment
Atom 1 Atom 2 Atom 3 Atom 4
rOH 0.958 0.000 1 2 1979Hoy/Bun:1 re
aHOH 104.4776 0.0019 2 1 3 1979Hoy/Bun:1 equilibrium

Cartesians
Atom x (Å) y (Å) z (Å)
O1 0.0000 0.0000 0.1173
H2 0.0000 0.7572 -0.4692
H3 0.0000 -0.7572 -0.4692

Atom - Atom Distances bond lengths
Distances in Å
  O1 H2 H3
O1   0.95780.9578
H2 0.9578   1.5144
H3 0.95781.5144  

Calculated geometries for H2O (Water).

Experimental Bond Angles (degrees) from cartesians bond angles

atom1 atom2 atom3 angle
H2 O1 H3 104.478

Bond descriptions


Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-O 2

Connectivity
Atom 1 Atom 2
O1 H2
O1 H3
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1   1A1
53800 1 1966Herzberg

Ionization Energies (eV)
Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
12.621 0.002     webbook

Proton Affinity (kJ mol-1)
Proton Affinity unc. reference comment
691.0   webbook  
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
Dipole (Debye) Reference comment
1.855 NISTTriatomic +-0.0004

Calculated electric dipole moments for H2O (Water).
Electric quadrupole moment quadrupole
Quadrupole (D Å) Reference comment
xx yy zz
-2.500 2.630 -0.130 1974Hel/Hel(II/6) aa=2.63+-0.02 bb=-0.13+-E28 cc=-2.5+-0.02

Calculated electric quadrupole moments for H2O (Water).
Electric dipole polarizability (Å3) polarizability
alpha unc. Reference
1.501   1997Oln/Can:59

Calculated electric dipole polarizability for H2O (Water).

References
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squib reference DOI
1966Herzberg Herzberg, G., Electronic spectra and electronic structure of polyatomic molecules,Van Nostrand,New York, 1966  
1974Hel/Hel(II/6) Hellwege, KH and AM Hellwege (eds.). Landolt-Bornstein: Group II: Volume 6 Molecular Constants from Microwave, Molecular Beam, and Electron Spin Resonance Spectroscopy Springer-Verlag. Berlin. 1974.  
1979Hoy/Bun:1 AR Hoy, PR Bunker, "A precise Solution of the Rotation Beninding Schrodinger Equation for a Triatomic Molecule with Application to the Water Molecule" J. Molecular Spectroscopy 74, 1-8, 1979 10.1016/0022-2852(79)90019-5
1979HUB/HER Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules,, Van Nostrand Reinhold Co., 1979  
1992Cul/Lie:502 F Culot, J Lievin "Ab initio Calculation of Vibrational Dipole Moment Matrix Elements. II. The Water Molecule as a Polyatomic Test Case" Physica Scripta 46, 502-517, 1992 10.1088/0031-8949/46/6/004
1997Oln/Can:59 TN Olney, NM Cann, G Cooper, CE Brion, Absolute scale determination for photoabsorption spectra and the calculation of molecular properties using dipole sum-rules, Chem. Phys. 223 (1997) 59-98 10.1016/S0301-0104(97)00145-6
2006Rus/Pin:6592 B Ruscic, RE Pinzon, ML Morton, NK Srinivasan, M-C Su, JW Sutherland, JV Michael "Active Thermochemical Tables: Accurate Enthalpy of Formation of Hydroperoxyl Radical, HO2" J. Phys. Chem. A 2006, 110, 6592-6601 10.1021/jp056311j
CODATA Cox, J.D.; Wagman, D.D.; Medvedev, V.A.CODATA Key Values for Thermodynamics. Hemisphere, New York, 1989  
NISTtriatomic NIST Triatomic Spectral Database (http://www.physics.nist.gov/PhysRefData/MolSpec/Triatomic/index.html)  
Shim Shimanouchi, T. , Tables of Molecular Vibrational Frequencies, Consolidated Volume 1, NSRDS NBS-39  
webbook NIST Chemistry Webbook (http://webbook.nist.gov/chemistry)  

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