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 Cu2 (Copper dimer)

State Conformation
1Σg D*H
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 485.34   kJ mol-1 webbook
Hfg(0K) enthalpy of formation     kJ mol-1 webbook
Entropy (298.15K) entropy 241.71   J K-1 mol-1 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
1 Σg 265 webbook      

vibrational zero-point energy: 132.3 cm-1
Calculated vibrational frequencies for Cu2 (Copper dimer).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
  0.10874   webbook Be

Calculated rotational constants for Cu2 (Copper dimer).

Product of moments of inertia moments of inertia
155.0227amu Å2   2.574252E-38gm cm2
Geometric Data
picture of Copper dimer

Point Group D∞h

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
rCuCu 2.220   1 2 webbook re


Atom x (Å) y (Å) z (Å)
Cu1 0.0000 0.0000 0.0000
Cu2 0.0000 0.0000 2.2197

Atom - Atom Distances bond lengths
Distances in Å

  Cu1 Cu2
Cu1   2.2197
Cu2 2.2197  

Calculated geometries for Cu2 (Copper dimer).

Bond descriptions

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


Atom 1 Atom 2
Cu1 Cu2
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1 webbook 1Σg
20433.2 2 webbook 1Π

Ionization Energies (eV)

Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
7.899 0.007     webbook

Electron Affinity (eV)

Electron Affinity unc. reference
0.840 0.150 webbook
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
For a molecule with D∞h symmetry there is no dipole.
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for Cu2 (Copper dimer).

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