return to home page

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

Listing of experimental data for BC (boron monocarbide)

Other names
Boron carbide;
InChI=1S/CB/c1-2 B#[C]
State Conformation
4Σ- C*V
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 828.43   kJ mol-1 webbook
Hfg(0K) enthalpy of formation     kJ mol-1 webbook
Entropy (298.15K) entropy 208.56   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

Calculated vibrational frequencies for BC (boron monocarbide).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
  1.32041   1990Fer/Obr:8482

Calculated rotational constants for BC (boron monocarbide).

Product of moments of inertia moments of inertia
12.76697amu Å2   2.120038E-39gm cm2

Geometric Data
picture of boron monocarbide

Point Group

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
rBC 1.491 0.000 1 2 1990Fer/Obr:8482

Atom x (Å) y (Å) z (Å)
B1 0.0000 0.0000 0.0000
C2 0.0000 0.0000 1.4912

Atom - Atom Distances bond lengths
Distances in Å
  B1 C2
B1   1.4912
C2 1.4912  

Calculated geometries for BC (boron monocarbide).

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

Atom 1 Atom 2
B1 C2

Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 4   4Σ-
2   2Π

Electron Affinity (eV)
Electron Affinity unc. reference
2.400 0.300 webbook

Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
Calculated electric dipole moments for BC (boron monocarbide).
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for BC (boron monocarbide).

By selecting the following links, you may be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to
squib reference DOI
1990Fer/Obr:8482 WTML Fernando, LC OBrien, PF Bernath " Fourier Transform emission spectroscopy : The B 4Sigma- to X 4Sigma- transition of BC" J. Chem. Phys. 93 (12) 8482 1990 10.1063/1.459287
webbook NIST Chemistry Webbook (  

Got a better number? Please email us at