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All results from a given calculation for C2H2 (Acetylene)

using model chemistry: CCSD(T)=FULL/6-31G

19 10 17 12 22

States and conformations

State Conformation minimum conformation conformer description state description
1 1 yes D*H 1Σg
Energy calculated at CCSD(T)=FULL/6-31G
 hartrees
Energy at 0K-76.999746
Energy at 298.15K-76.999414
HF Energy-76.789191
Nuclear repulsion energy24.297280
The energy at 298.15K was derived from the energy at 0K and an integrated heat capacity that used the calculated vibrational frequencies.
Vibrational Frequencies calculated at CCSD(T)=FULL/6-31G
Mode Number Symmetry Frequency
(cm-1)
Scaled Frequency
(cm-1)
IR Intensities
(km mol-1)
Raman Act
(Å4/u)
Dep P Dep U
1 Σg 3464 3464        
2 Σg 1963 1963        
3 Σu 3365 3365        
4 Πg 366 366        
4 Πg 366 366        
5 Πu 703 703        
5 Πu 703 703        

Unscaled Zero Point Vibrational Energy (zpe) 5464.5 cm-1
Scaled (by 1) Zero Point Vibrational Energy (zpe) 5464.5 cm-1
See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.
Rotational Constants (cm-1) from geometry optimized at CCSD(T)=FULL/6-31G
B
1.13563

See section I.F.4 to change rotational constant units
Geometric Data calculated at CCSD(T)=FULL/6-31G

Point Group is D∞h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 0.000 0.615
C2 0.000 0.000 -0.615
H3 0.000 0.000 1.690
H4 0.000 0.000 -1.690

Atom - Atom Distances (Å)
  C1 C2 H3 H4
C11.23071.07452.3053
C21.23072.30531.0745
H31.07452.30533.3798
H42.30531.07453.3798

picture of Acetylene state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 H4 180.000 C2 C1 H3 180.000
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability