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 SiH2(CH3)2 (dimethylsilane)

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
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

Calculated vibrational frequencies for SiH2(CH3)2 (dimethylsilane).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment

Calculated rotational constants for SiH2(CH3)2 (dimethylsilane).

Product of moments of inertia moments of inertia
amu3Å6   0gm3 cm6
Geometric Data
picture of dimethylsilane

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
rSiC 1.868 0.001 1 4 1998Kuc
rSiH 1.482 0.001 1 2 1998Kuc
rCH 1.089   5 7 1998Kuc assumed
rCH 1.089 0.003 5 7 1998Kuc
aCSiC 110.93 0.07 4 1 5 1998Kuc
aCSiH 109.5 0.03 2 1 5 1998Kuc
aHSiH 107.83 0.08 2 1 3 1998Kuc
aHCSi 110.85 0.4 1 4 6 1998Kuc
aHCSi 111.07 0.23 1 5 10 1998Kuc
aHCH 107.78 0.57 7 5 10 1998Kuc
aHCH 108.08 0.65 10 5 11 1998Kuc

These cartesians were determined using some assumed coordinate values. Cartesians

Atom x (Å) y (Å) z (Å)

Atom - Atom Distances bond lengths
Distances in Å


Calculated geometries for SiH2(CH3)2 (dimethylsilane).

Bond descriptions

Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
C-Si 2
H-Si 2
H-C 6


Atom 1 Atom 2
Si1 H2
Si1 H3
Si1 C4
Si1 C5
C4 H6
C4 H8
C4 H9
C5 H7
C5 H10
C5 H11
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1   1A1

Ionization Energies (eV)

Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
10.300       webbook
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
Dipole (Debye) Reference comment
0.750 NSRDS-NBS10  

Calculated electric dipole moments for SiH2(CH3)2 (dimethylsilane).
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for SiH2(CH3)2 (dimethylsilane).

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squib reference DOI
1998Kuc K Kuchitsu(ed) "Structure of Free Polyatomic Molecules - Basic Data" Springer, Berlin, 1998  
NSRDS-NBS10 R. D. Nelson Jr., D. R. Lide, A. A. Maryott "Selected Values of electric dipole moments for molecules in the gas phase" NSRDS-NBS10, 1967  
webbook NIST Chemistry Webbook (  

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