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All results from a given calculation for C4H4N2 (Pyrazine)

using model chemistry: MP2/CEP-31G*

19 10 17 12 22

States and conformations

State Conformation minimum conformation conformer description state description
1 1 yes D2H 1Ag
Energy calculated at MP2/CEP-31G*
 hartrees
Energy at 0K-44.392869
Energy at 298.15K-44.398645
HF Energy-43.612229
Nuclear repulsion energy104.044007
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 MP2/CEP-31G*
Mode Number Symmetry Frequency
(cm-1)
Scaled Frequency
(cm-1)
IR Intensities
(km mol-1)
Raman Act
4/u)
Dep P Dep U
1 Ag 3230 3067 0.00      
2 Ag 1622 1540 0.00      
3 Ag 1250 1187 0.00      
4 Ag 1013 962 0.00      
5 Ag 593 563 0.00      
6 Au 913 866 0.00      
7 Au 340 323 0.00      
8 B1g 942 895 0.00      
9 B1u 3203 3041 4.41      
10 B1u 1488 1413 1.17      
11 B1u 1151 1093 7.98      
12 B1u 1024 972 28.55      
13 B2g 921 874 0.00      
14 B2g 753 715 0.00      
15 B2u 3222 3059 66.34      
16 B2u 1440 1367 43.24      
17 B2u 1351 1283 0.04      
18 B2u 1078 1024 5.55      
19 B3g 3196 3034 0.00      
20 B3g 1542 1464 0.00      
21 B3g 1351 1283 0.00      
22 B3g 692 657 0.00      
23 B3u 801 760 52.56      
24 B3u 420 398 22.32      

Unscaled Zero Point Vibrational Energy (zpe) 16767.7 cm-1
Scaled (by 0.9494) Zero Point Vibrational Energy (zpe) 15919.2 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 MP2/CEP-31G*
ABC
0.21007 0.18818 0.09926

See section I.F.4 to change rotational constant units
Geometric Data calculated at MP2/CEP-31G*

Point Group is D2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
N1 0.000 0.000 1.447
N2 0.000 0.000 -1.447
C3 0.000 1.143 0.713
C4 0.000 -1.143 0.713
C5 0.000 -1.143 -0.713
C6 0.000 1.143 -0.713
H7 0.000 2.087 1.272
H8 0.000 -2.087 1.272
H9 0.000 -2.087 -1.272
H10 0.000 2.087 -1.272

Atom - Atom Distances (Å)
  N1 N2 C3 C4 C5 C6 H7 H8 H9 H10
N12.89401.35811.35812.44392.44392.09392.09393.42763.4276
N22.89402.44392.44391.35811.35813.42763.42762.09392.0939
C31.35812.44392.28572.69431.42651.09693.27753.79102.1985
C41.35812.44392.28571.42652.69433.27751.09692.19853.7910
C52.44391.35812.69431.42652.28573.79102.19851.09693.2775
C62.44391.35811.42652.69432.28572.19853.79103.27751.0969
H72.09393.42761.09693.27753.79102.19854.17324.88782.5447
H82.09393.42763.27751.09692.19853.79104.17322.54474.8878
H93.42762.09393.79102.19851.09693.27754.88782.54474.1732
H103.42762.09392.19853.79103.27751.09692.54474.88784.1732

picture of Pyrazine state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
N1 C3 C6 122.701 N1 C3 H7 116.655
N1 C4 C5 122.701 N1 C4 H8 116.655
N2 C5 C4 122.701 N2 C5 H9 116.655
N2 C6 C3 122.701 N2 C6 H10 116.655
C3 N1 C4 114.598 C3 C6 H10 120.644
C4 C5 H9 120.644 C5 N2 C6 114.598
C5 C4 H8 120.644 C6 C3 H7 120.644
Electronic energy levels

Electronic state

Charges, Dipole, Quadrupole and Polarizability