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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 C2H2N4 (sym-tetrazine)

Other names
1,2,4,5-Tetrazine; s-Tetrazine;
InChI=1S/C2H2N4/c1-3-5-2-6-4-1/h1-2H HTJMXYRLEDBSLT-UHFFFAOYSA-N C1=NN=CN=N1 1,2,4,5-Tetrazine
State Conformation
1Ag D2H
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
1 Ag 3010 1988Inn/Ros:492      
2 Ag 1415 1988Inn/Ros:492      
3 Ag 1009 1988Inn/Ros:492      
4 Ag 736 1988Inn/Ros:492      
5 Au 335 1988Inn/Ros:492      
6 B1u 3086 1988Inn/Ros:492      
7 B1u 1204 1988Inn/Ros:492      
8 B1u 1093 1988Inn/Ros:492      
9 B2g 994 1988Inn/Ros:492      
10 B2g 801 1988Inn/Ros:492      
11 B2u 1448 1988Inn/Ros:492      
12 B2u 1104 1988Inn/Ros:492      
13 B2u 883 1988Inn/Ros:492      
14 B3g 1525 1988Inn/Ros:492      
15 B3g 1290 1988Inn/Ros:492      
16 B3g 640 1988Inn/Ros:492      
17 B3u 929 1988Inn/Ros:492      
18 B3u 254 1988Inn/Ros:492      

vibrational zero-point energy: 10878.0 cm-1
Calculated vibrational frequencies for C2H2N4 (sym-tetrazine).
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 C2H2N4 (sym-tetrazine).

Product of moments of inertia moments of inertia
amu3Å6   0gm3 cm6
Geometric Data
picture of sym-tetrazine

Point Group D2h

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


Atom x (Å) y (Å) z (Å)

Atom - Atom Distances bond lengths
Distances in Å


Calculated geometries for C2H2N4 (sym-tetrazine).

Bond descriptions

Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
N:N 2
C:N 4
H-C 2


Atom 1 Atom 2
C1 C2
C1 N3
C1 H7
C2 N5
C2 N6
C2 H8
N3 N6
N4 N5
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description

Ionization Energies (eV)

Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
9.140       webbook
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
For a molecule with D2h symmetry there is no dipole.
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for C2H2N4 (sym-tetrazine).

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squib reference DOI
1988Inn/Ros:492 KK Innes, IG Ross, WR Moomaw "Electronic States of Azabenzenes and Azanaphthalenes: A Revised and Extended Critical Review" J. Mol. Spect. 132, 492-544 (1988) 10.1016/0022-2852(88)90343-8
webbook NIST Chemistry Webbook (  

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