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All results from a given calculation for C4H4 (cyclobutadiene)

using model chemistry: B97D3/6-31G*

19 10 17 12 22

States and conformations

State Conformation minimum conformation conformer description state description
1 1 yes D2H 1Ag
1 2 no D4H 1A1g

Conformer 1 (D2H)

Jump to S1C2
Energy calculated at B97D3/6-31G*
 hartrees
Energy at 0K-154.568436
Energy at 298.15K-154.571332
HF Energy-154.568436
Nuclear repulsion energy 
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 B97D3/6-31G*
Mode Number Symmetry Frequency
(cm-1)		 Scaled Frequency
(cm-1)		 IR Intensities
(km mol-1)		 Raman Act
(Å4/u)		 Dep P Dep U
1 Ag 3198 3135 0.00      
2 Ag 1604 1572 0.00      
3 Ag 1095 1074 0.00      
4 Ag 939 921 0.00      
5 Au 824 808 0.00      
6 Au 525 514 0.00      
7 B1g 794 779 0.00      
8 B1u 3186 3123 47.67      
9 B1u 1608 1576 3.57      
10 B1u 1044 1024 0.02      
11 B2g 548 537 0.00      
12 B2u 3165 3103 29.61      
13 B2u 1237 1212 34.07      
14 B2u 667 654 5.96      
15 B3g 3148 3087 0.00      
16 B3g 1149 1126 0.00      
17 B3g 848 831 0.00      
18 B3u 554 544 112.95      

Unscaled Zero Point Vibrational Energy (zpe) 13065.6 cm-1
Scaled (by 0.9804) Zero Point Vibrational Energy (zpe) 12809.5 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 B97D3/6-31G*
ABC
0.56066 0.42136 0.24057

See section I.F.4 to change rotational constant units
Geometric Data calculated at B97D3/6-31G*

Point Group is D2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 0.671 0.794
C2 0.000 0.671 -0.794
C3 0.000 -0.671 0.794
C4 0.000 -0.671 -0.794
H5 0.000 1.447 1.557
H6 0.000 1.447 -1.557
H7 0.000 -1.447 1.557
H8 0.000 -1.447 -1.557

Atom - Atom Distances (Å)
  C1 C2 C3 C4 H5 H6 H7 H8
C11.58721.34252.07881.08862.47562.25173.1645
C21.58722.07881.34252.47561.08863.16452.2517
C31.34252.07881.58722.25173.16451.08862.4756
C42.07881.34251.58723.16452.25172.47561.0886
H51.08862.47562.25173.16453.11482.89384.2516
H62.47561.08863.16452.25173.11484.25162.8938
H72.25173.16451.08862.47562.89384.25163.1148
H83.16452.25172.47561.08864.25162.89383.1148

picture of cyclobutadiene state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 C4 90.000 C1 C2 H6 134.573
C1 C3 C4 90.000 C1 C3 H7 135.427
C2 C1 C3 90.000 C2 C1 H5 134.573
C2 C4 C3 90.000 C3 C1 H5 135.427
C4 C2 H6 135.427 C4 C3 H7 134.573
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at B97D3/6-31G* Charges (e)
Number Element Mulliken CHELPG AIM ESP
1 C -0.138      
2 C -0.138      
3 C -0.138      
4 C -0.138      
5 H 0.138      
6 H 0.138      
7 H 0.138      
8 H 0.138      


Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)
  x y z Total
  0.000 0.000 0.000 0.000
CHELPG        
AIM        
ESP        


Electric Quadrupole moment
Quadrupole components in D Å
Primitive
 xyz
x -25.891 0.000 0.000
y 0.000 -20.518 0.000
z 0.000 0.000 -21.528
Traceless
 xyz
x -4.868 0.000 0.000
y 0.000 3.192 0.000
z 0.000 0.000 1.676
Polar
3z2-r23.352
x2-y2-5.373
xy0.000
xz0.000
yz0.000


Polarizabilities
Components of the polarizability tensor.
Units are Å3 (Angstrom cubed)
Change units.
  x y z
x 2.334 0.000 0.000
y 0.000 7.034 0.000
z 0.000 0.000 5.720


<r2> (average value of r2) Å2
<r2> 58.149
(<r2>)1/2 7.626

Conformer 2 (D4H)

Jump to S1C1
Energy calculated at B97D3/6-31G*
 hartrees
Energy at 0K-154.568436
Energy at 298.15K-154.571331
HF Energy-154.568436
Nuclear repulsion energy 
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 B97D3/6-31G*
Mode Number Symmetry Frequency
(cm-1)		 Scaled Frequency
(cm-1)		 IR Intensities
(km mol-1)		 Raman Act
(Å4/u)		 Dep P Dep U
1 Ag 3198 3135 0.00      
2 Ag 1604 1573 0.00      
3 Ag 1095 1074 0.00      
4 Ag 939 920 0.00      
5 Au 824 808 0.00      
6 Au 524 514 0.00      
7 B1g 794 779 0.00      
8 B1u 3186 3123 47.69      
9 B1u 1609 1577 3.58      
10 B1u 1044 1024 0.01      
11 B2g 548 537 0.00      
12 B2u 3165 3102 29.62      
13 B2u 1237 1212 34.10      
14 B2u 666 653 5.96      
15 B3g 3148 3087 0.00      
16 B3g 1149 1126 0.00      
17 B3g 848 831 0.00      
18 B3u 554 544 112.98      

Unscaled Zero Point Vibrational Energy (zpe) 13065.8 cm-1
Scaled (by 0.9804) Zero Point Vibrational Energy (zpe) 12809.7 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 B97D3/6-31G*
ABC
0.56083 0.42123 0.24055

See section I.F.4 to change rotational constant units
Geometric Data calculated at B97D3/6-31G*

Point Group is D2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 0.671 0.794
C2 0.000 0.671 -0.794
C3 0.000 -0.671 0.794
C4 0.000 -0.671 -0.794
H5 0.000 1.447 1.558
H6 0.000 1.447 -1.558
H7 0.000 -1.447 1.558
H8 0.000 -1.447 -1.558

Atom - Atom Distances (Å)
  C1 C2 C3 C4 H5 H6 H7 H8
C11.58741.34232.07891.08862.47602.25143.1645
C21.58742.07891.34232.47601.08863.16452.2514
C31.34232.07891.58742.25143.16451.08862.4760
C42.07891.34231.58743.16452.25142.47601.0886
H51.08862.47602.25143.16453.11552.89324.2517
H62.47601.08863.16452.25143.11554.25172.8932
H72.25143.16451.08862.47602.89324.25173.1155
H83.16452.25142.47601.08864.25172.89323.1155

picture of cyclobutadiene state 1 conformation 2
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 C4 90.000 C1 C2 H6 135.250
C1 C3 C4 90.000 C1 C3 H7 134.750
C2 C1 C3 90.000 C2 C1 H5 135.250
C2 C4 C3 90.000 C3 C1 H5 134.750
C4 C2 H6 134.750 C4 C3 H7 135.250
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at B97D3/6-31G* Charges (e)
Number Element Mulliken CHELPG AIM ESP
1 C -0.138      
2 C -0.138      
3 C -0.138      
4 C -0.138      
5 H 0.138      
6 H 0.138      
7 H 0.138      
8 H 0.138      


Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)
  x y z Total
  0.000 0.000 0.000 0.000
CHELPG        
AIM        
ESP        


Electric Quadrupole moment
Quadrupole components in D Å
Primitive
 xyz
x -25.890 0.000 0.000
y 0.000 -20.521 0.000
z 0.000 0.000 -21.524
Traceless
 xyz
x -4.868 0.000 0.000
y 0.000 3.186 0.000
z 0.000 0.000 1.682
Polar
3z2-r23.363
x2-y2-5.369
xy0.000
xz0.000
yz0.000


Polarizabilities
Components of the polarizability tensor.
Units are Å3 (Angstrom cubed)
Change units.
  x y z
x 2.334 0.000 0.000
y 0.000 7.032 0.000
z 0.000 0.000 5.722


<r2> (average value of r2) Å2
<r2> 58.151
(<r2>)1/2 7.626