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All results from a given calculation for C4H4N2 (Pyrazine)

using model chemistry: MP2/3-21G*

19 10 17 12 22

States and conformations

State Conformation minimum conformation conformer description state description
1 1 yes D2H 1Ag
Energy calculated at MP2/3-21G*
 hartrees
Energy at 0K-261.759619
Energy at 298.15K-261.765512
HF Energy-261.189516
Nuclear repulsion energy205.356189
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 MP2/3-21G*
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 3237 3079 0.00      
2 Ag 1538 1463 0.00      
3 Ag 1272 1210 0.00      
4 Ag 979 931 0.00      
5 Ag 626 596 0.00      
6 Au 1017 967 0.00      
7 Au 353 336 0.00      
8 B1g 966 919 0.00      
9 B1u 3213 3056 12.07      
10 B1u 1503 1430 19.81      
11 B1u 1157 1101 2.68      
12 B1u 985 937 24.12      
13 B2g 1010 961 0.00      
14 B2g 791 752 0.00      
15 B2u 3228 3071 40.60      
16 B2u 1443 1372 22.59      
17 B2u 1153 1097 11.42      
18 B2u 1048 997 5.09      
19 B3g 3208 3052 0.00      
20 B3g 1468 1396 0.00      
21 B3g 1383 1316 0.00      
22 B3g 725 689 0.00      
23 B3u 820 780 36.79      
24 B3u 440 419 23.57      

Unscaled Zero Point Vibrational Energy (zpe) 16780.9 cm-1
Scaled (by 0.9513) Zero Point Vibrational Energy (zpe) 15963.7 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 MP2/3-21G*
ABC
0.20482 0.19364 0.09954

See section I.F.4 to change rotational constant units
Geometric Data calculated at MP2/3-21G*

Point Group is D2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
N1 0.000 0.000 1.428
N2 0.000 0.000 -1.428
C3 0.000 1.161 0.700
C4 0.000 -1.161 0.700
C5 0.000 -1.161 -0.700
C6 0.000 1.161 -0.700
H7 0.000 2.089 1.261
H8 0.000 -2.089 1.261
H9 0.000 -2.089 -1.261
H10 0.000 2.089 -1.261

Atom - Atom Distances (Å)
  N1 N2 C3 C4 C5 C6 H7 H8 H9 H10
N12.85691.37081.37082.42432.42432.09592.09593.40563.4056
N22.85692.42432.42431.37081.37083.40563.40562.09592.0959
C31.37082.42432.32212.71131.39951.08473.29843.79592.1694
C41.37082.42432.32211.39952.71133.29841.08472.16943.7959
C52.42431.37082.71131.39952.32213.79592.16941.08473.2984
C62.42431.37081.39952.71132.32212.16943.79593.29841.0847
H72.09593.40561.08473.29843.79592.16944.17854.88062.5221
H82.09593.40563.29841.08472.16943.79594.17852.52214.8806
H93.40562.09593.79592.16941.08473.29844.88062.52214.1785
H103.40562.09592.16943.79593.29841.08472.52214.88064.1785

picture of Pyrazine state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
N1 C3 C6 122.112 N1 C3 H7 116.726
N1 C4 C5 122.112 N1 C4 H8 116.726
N2 C5 C4 122.112 N2 C5 H9 116.726
N2 C6 C3 122.112 N2 C6 H10 116.726
C3 N1 C4 115.777 C3 C6 H10 121.162
C4 C5 H9 121.162 C5 N2 C6 115.777
C5 C4 H8 121.162 C6 C3 H7 121.162
Electronic energy levels

Electronic state

Charges, Dipole, Quadrupole and Polarizability