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All results from a given calculation for C4H4N2 (Pyrazine)

using model chemistry: MP2/6-31G*

19 10 17 12 22

States and conformations

State Conformation minimum conformation conformer description state description
1 1 yes D2H 1Ag
Energy calculated at MP2/6-31G*
 hartrees
Energy at 0K-263.503627
Energy at 298.15K-263.509471
HF Energy-262.679163
Nuclear repulsion energy207.883671
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 MP2/6-31G*
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 3245 3060 0.00      
2 Ag 1641 1547 0.00      
3 Ag 1281 1208 0.00      
4 Ag 1041 982 0.00      
5 Ag 605 571 0.00      
6 Au 960 905 0.00      
7 Au 344 324 0.00      
8 B1g 944 890 0.00      
9 B1u 3226 3042 5.67      
10 B1u 1531 1444 4.01      
11 B1u 1176 1109 3.14      
12 B1u 1040 981 37.87      
13 B2g 949 895 0.00      
14 B2g 747 704 0.00      
15 B2u 3240 3055 48.79      
16 B2u 1471 1387 33.87      
17 B2u 1364 1287 0.13      
18 B2u 1113 1049 12.02      
19 B3g 3225 3042 0.00      
20 B3g 1588 1498 0.00      
21 B3g 1396 1316 0.00      
22 B3g 718 677 0.00      
23 B3u 801 755 27.12      
24 B3u 424 400 24.34      

Unscaled Zero Point Vibrational Energy (zpe) 17033.5 cm-1
Scaled (by 0.943) Zero Point Vibrational Energy (zpe) 16062.6 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 MP2/6-31G*
ABC
0.21288 0.19596 0.10203

See section I.F.4 to change rotational constant units
Geometric Data calculated at MP2/6-31G*

Point Group is D2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
N1 0.000 0.000 1.409
N2 0.000 0.000 -1.409
C3 0.000 1.139 0.700
C4 0.000 -1.139 0.700
C5 0.000 -1.139 -0.700
C6 0.000 1.139 -0.700
H7 0.000 2.073 1.260
H8 0.000 -2.073 1.260
H9 0.000 -2.073 -1.260
H10 0.000 2.073 -1.260

Atom - Atom Distances (Å)
  N1 N2 C3 C4 C5 C6 H7 H8 H9 H10
N12.81841.34181.34182.39712.39712.07872.07873.37963.3796
N22.81842.39712.39711.34181.34183.37963.37962.07872.0787
C31.34182.39712.27812.67381.39991.08913.26083.76292.1710
C41.34182.39712.27811.39992.67383.26081.08912.17103.7629
C52.39711.34182.67381.39992.27813.76292.17101.08913.2608
C62.39711.34181.39992.67382.27812.17103.76293.26081.0891
H72.07873.37961.08913.26083.76292.17104.14674.85212.5195
H82.07873.37963.26081.08912.17103.76294.14672.51954.8521
H93.37962.07873.76292.17101.08913.26084.85212.51954.1467
H103.37962.07872.17103.76293.26081.08912.51954.85214.1467

picture of Pyrazine state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
N1 C3 C6 121.909 N1 C3 H7 117.164
N1 C4 C5 121.909 N1 C4 H8 117.164
N2 C5 C4 121.909 N2 C5 H9 117.164
N2 C6 C3 121.909 N2 C6 H10 117.164
C3 N1 C4 116.183 C3 C6 H10 120.928
C4 C5 H9 120.928 C5 N2 C6 116.183
C5 C4 H8 120.928 C6 C3 H7 120.928
Electronic energy levels

Electronic state

Charges, Dipole, Quadrupole and Polarizability