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All results from a given calculation for C4H4 (cyclobutadiene)

using model chemistry: TPSSh/cc-pVTZ

19 10 17 12 22

States and conformations

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

Conformer 1 (D2H)

Jump to S1C2
Energy calculated at TPSSh/cc-pVTZ
 hartrees
Energy at 0K-154.745611
Energy at 298.15K-154.748690
HF Energy-154.745611
Nuclear repulsion energy98.919210
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 TPSSh/cc-pVTZ
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 3233 3131 0.00      
2 Ag 1625 1573 0.00      
3 Ag 1115 1079 0.00      
4 Ag 958 928 0.00      
5 Au 883 855 0.00      
6 Au 534 517 0.00      
7 B1g 884 856 0.00      
8 B1u 3222 3120 26.73      
9 B1u 1631 1579 5.06      
10 B1u 1064 1030 0.05      
11 B2g 607 587 0.00      
12 B2u 3200 3099 17.37      
13 B2u 1268 1228 38.98      
14 B2u 709 686 8.94      
15 B3g 3184 3083 0.00      
16 B3g 1188 1150 0.00      
17 B3g 843 816 0.00      
18 B3u 592 574 125.56      

Unscaled Zero Point Vibrational Energy (zpe) 13369.8 cm-1
Scaled (by 0.9683) Zero Point Vibrational Energy (zpe) 12945.9 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 TPSSh/cc-pVTZ
ABC
0.57073 0.42776 0.24450

See section I.F.4 to change rotational constant units
Geometric Data calculated at TPSSh/cc-pVTZ

Point Group is D2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 0.666 0.787
C2 0.000 0.666 -0.787
C3 0.000 -0.666 0.787
C4 0.000 -0.666 -0.787
H5 0.000 1.434 1.548
H6 0.000 1.434 -1.548
H7 0.000 -1.434 1.548
H8 0.000 -1.434 -1.548

Atom - Atom Distances (Å)
  C1 C2 C3 C4 H5 H6 H7 H8
C11.57441.33152.06191.08112.45812.23333.1402
C21.57442.06191.33152.45811.08113.14022.2333
C31.33152.06191.57442.23333.14021.08112.4581
C42.06191.33151.57443.14022.23332.45811.0811
H51.08112.45812.23333.14023.09532.86834.2200
H62.45811.08113.14022.23333.09534.22002.8683
H72.23333.14021.08112.45812.86834.22003.0953
H83.14022.23332.45811.08114.22002.86833.0953

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 134.701
C1 C3 C4 90.000 C1 C3 H7 135.299
C2 C1 C3 90.000 C2 C1 H5 134.701
C2 C4 C3 90.000 C3 C1 H5 135.299
C4 C2 H6 135.299 C4 C3 H7 134.701
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at TPSSh/cc-pVTZ Charges (e)
Number Element Mulliken CHELPG AIM ESP
1 C -0.098      
2 C -0.098      
3 C -0.098      
4 C -0.098      
5 H 0.098      
6 H 0.098      
7 H 0.098      
8 H 0.098      


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


Polarizabilities
Components of the polarizability tensor.
Units are Å3 (Angstrom cubed)
Change units.
  x y z
x 3.736 0.000 0.000
y 0.000 7.511 0.000
z 0.000 0.000 6.394


<r2> (average value of r2) Å2
<r2> 57.761
(<r2>)1/2 7.600

Conformer 2 (D4H)

Jump to S1C1
Energy calculated at TPSSh/cc-pVTZ
 hartrees
Energy at 0K-154.745611
Energy at 298.15K-154.748690
HF Energy-154.745611
Nuclear repulsion energy98.919260
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 TPSSh/cc-pVTZ
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 3233 3131 0.00      
2 Ag 3184 3083 0.00      
3 Ag 1625 1573 0.00      
4 Ag 1188 1151 0.00      
5 Ag 1115 1079 0.00      
6 Ag 958 928 0.00      
7 Ag 843 816 0.00      
8 Au 883 855 0.00      
9 Au 592 573 125.62      
10 Au 534 517 0.00      
11 Bg 884 856 0.00      
12 Bg 606 587 0.00      
13 Bu 3222 3120 26.68      
14 Bu 3201 3099 17.34      
15 Bu 1631 1579 5.07      
16 Bu 1268 1228 38.98      
17 Bu 1064 1030 0.05      
18 Bu 709 686 8.98      

Unscaled Zero Point Vibrational Energy (zpe) 13369.6 cm-1
Scaled (by 0.9683) Zero Point Vibrational Energy (zpe) 12945.8 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 TPSSh/cc-pVTZ
ABC
0.57082 0.42771 0.24450

See section I.F.4 to change rotational constant units
Geometric Data calculated at TPSSh/cc-pVTZ

Point Group is C2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 -0.714 0.804 0.000
C2 -0.714 -0.633 0.000
C3 0.714 0.633 0.000
C4 0.714 -0.804 0.000
H5 -1.427 1.609 0.000
H6 -1.524 -1.352 0.000
H7 1.524 1.352 0.000
H8 1.427 -1.609 0.000

Atom - Atom Distances (Å)
  C1 C2 C3 C4 H5 H6 H7 H8
C11.43741.43732.15061.07482.30372.30373.2254
C21.43741.90751.43732.35211.08362.99112.3521
C31.43731.90751.43742.35212.99111.08362.3521
C42.15061.43731.43743.22542.30372.30371.0748
H51.07482.35212.35213.22542.96202.96204.3002
H62.30371.08362.99112.30372.96204.07472.9620
H72.30372.99111.08362.30372.96204.07472.9620
H83.22542.35212.35211.07484.30022.96202.9620

picture of cyclobutadiene state 1 conformation 2
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 C4 96.856 C1 C2 H6 131.572
C1 C3 C4 96.856 C1 C3 H7 131.572
C2 C1 C3 83.144 C2 C1 H5 138.428
C2 C4 C3 83.144 C3 C1 H5 138.428
C4 C2 H6 131.572 C4 C3 H7 131.572
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at TPSSh/cc-pVTZ Charges (e)
Number Element Mulliken CHELPG AIM ESP
1 C -0.098      
2 C -0.098      
3 C -0.098      
4 C -0.098      
5 H 0.098      
6 H 0.098      
7 H 0.098      
8 H 0.098      


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


Polarizabilities
Components of the polarizability tensor.
Units are Å3 (Angstrom cubed)
Change units.
  x y z
x 7.509 -0.000 0.000
y -0.000 6.395 0.000
z 0.000 0.000 3.736


<r2> (average value of r2) Å2
<r2> 57.761
(<r2>)1/2 7.600