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

Listing of experimental data for As2 (Arsenic diatomic)

InChI=1S/As2/c1-2 [As]#[As]
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 221.00 15.00 kJ mol-1 1973Kor/Gin:135
Hfg(0K) enthalpy of formation   15.00 kJ mol-1 1973Kor/Gin:135
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 Σ 430 webbook      

vibrational zero-point energy: 214.8 cm-1
Calculated vibrational frequencies for As2 (Arsenic diatomic).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
  0.10179   webbook

Calculated rotational constants for As2 (Arsenic diatomic).

Product of moments of inertia moments of inertia
165.6118amu Å2   2.750092E-38gm cm2

Geometric Data
picture of Arsenic diatomic

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
rAsAs 2.103   1 2 webbook re

Atom x (Å) y (Å) z (Å)
As1 0.0000 0.0000 0.0000
As2 0.0000 0.0000 2.1026

Atom - Atom Distances bond lengths
Distances in Å
  As1 As2
As1   2.1026
As2 2.1026  

Calculated geometries for As2 (Arsenic diatomic).

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

Atom 1 Atom 2
As1 As2

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
10.000 0.200     webbook

Electron Affinity (eV)
Electron Affinity unc. reference
0.739 0.008 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 As2 (Arsenic diatomic).

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squib reference DOI
1973Kor/Gin:135 J Kordis, KA Gingerich "Atomization Energy and Standard Heat of Formation of Gaseous Diatomic Arsenic" J. Chemical and Engineering Data 18(2), 135, 1973 10.1021/je60057a023
webbook NIST Chemistry Webbook (  

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