National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
XOlder CCCBDB versions
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers

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II.A.1. (XV.A.)

Listing of experimental data for MgOH (magnesium hydroxide)

Other names
Magnesium hydroxide;
InChI=1/Mg.H2O/h;1H2/q+1;/p-1/rHMgO/c1-2/h2H UNYOJUYSNFGNDV-MGFXJTNPNA-M
State Conformation
2A' CS
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 -94.45 33.00 kJ mol-1 1989OPE/TEW9152 Entropy and HH from Gurvich.
Hfg(0K) enthalpy of formation -92.00 33.00 kJ mol-1 1989OPE/TEW9152 Entropy and HH from Gurvich.
Entropy (298.15K) entropy 232.62 8.40 J K-1 mol-1 Gurvich
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 11.12   kJ mol-1 Gurvich
Heat Capacity (298.15K) heat capacity 42.99   J K-1 mol-1 webbook Entropy and HH from Gurvich. Cp from Webbook
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
2 Σ 750 VEEL5      
3 Π 188 VEEL5      

Calculated vibrational frequencies for MgOH (magnesium hydroxide).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
  0.50158   1999App/And:10919

Calculated rotational constants for MgOH (magnesium hydroxide).

Product of moments of inertia moments of inertia
33.60937amu Å2   5.581055E-39gm cm2
Geometric Data
picture of magnesium hydroxide

Point Group C∞v

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
rMgO 1.767   1 2 1999App/And:10919 re structure
rOH 0.940   1 3 1992Bar/And:225 re
aHOMg 180 2 1 3 1999App/And:10919 quasilinear


Atom x (Å) y (Å) z (Å)
O1 0.0000 0.0000 0.0000
Mg2 0.0000 0.0000 1.7670
H3 0.0000 0.0000 -0.9400

Atom - Atom Distances bond lengths
Distances in Å

  O1 Mg2 H3
O1   1.76700.9400
Mg2 1.7670   2.7070
H3 0.94002.7070  

Calculated geometries for MgOH (magnesium hydroxide).

Experimental Bond Angles (degrees) from cartesians bond angles

atom1 atom2 atom3 angle
Mg2 O1 H3 180.000

Bond descriptions

Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-O 1
O-Mg 1


Atom 1 Atom 2
O1 Mg2
O1 H3
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 2   2A'

Ionization Energies (eV)

Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
7.500 0.300     webbook
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
Calculated electric dipole moments for MgOH (magnesium hydroxide).
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for MgOH (magnesium hydroxide).

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squib reference DOI
1989OPE/TEW9152 Operti, L; Tews, EC; MacMahon, TJ; Freiser, BS, Thermochemical properties of Gas-Phase MgOH and MgO determined by FTMS. JACS 111, 9152, 1989 10.1021/ja00208a002
1992Bar/And:225 Barclay, W.L.; Anderson, M.A.; Ziurys, L.M. "The millimeter-wave spectrum of the MgOH radical." Chemical Physics Letters. 196, 225-232 (1992) 10.1016/0009-2614(92)85959-E
1999App/And:10919 AJ Apponi, MA Anderson, LM Ziurys "High resolution spectroscopy of MgOH (X 2Sigma+) in its v2 mode: Further evidence for quasilinearity" J. Chem. Phys. 111, 10919, 1999 10.1063/1.480455
Gurvich Gurvich, L.V.; Veyts, I. V.; Alcock, C. B., Thermodynamic Properties of Individual Substances, Fouth Edition, Hemisphere Pub. Co., New York, 1989 10.1351/pac198961061027
VEEL5 M.E. Jacox, Vibrational and Electronic Energy Levels of Polyatomic Transient Molecules, J. Phys. Chem.Ref. Data, Monograph 3 (1994) (updated data in NIST Chemistry Webbook -  
webbook NIST Chemistry Webbook (  

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