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All results from a given calculation for C4H4N2 (Pyrazine)

using model chemistry: MP2/6-31G(2df,p)

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(2df,p)
 hartrees
Energy at 0K-263.678087
Energy at 298.15K-263.683979
HF Energy-262.704342
Nuclear repulsion energy208.477595
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(2df,p)
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 3240 3061 0.00      
2 Ag 1616 1526 0.00      
3 Ag 1264 1194 0.00      
4 Ag 1033 976 0.00      
5 Ag 596 563 0.00      
6 Au 1003 947 0.00      
7 Au 347 328 0.00      
8 B1g 958 905 0.00      
9 B1u 3221 3042 2.06      
10 B1u 1509 1425 2.74      
11 B1u 1166 1101 2.63      
12 B1u 1030 973 40.66      
13 B2g 992 937 0.00      
14 B2g 771 728 0.00      
15 B2u 3236 3056 35.69      
16 B2u 1449 1368 33.44      
17 B2u 1374 1297 0.10      
18 B2u 1092 1032 11.16      
19 B3g 3221 3042 0.00      
20 B3g 1567 1480 0.00      
21 B3g 1377 1301 0.00      
22 B3g 708 669 0.00      
23 B3u 816 771 20.56      
24 B3u 426 403 22.77      

Unscaled Zero Point Vibrational Energy (zpe) 17005.2 cm-1
Scaled (by 0.9445) Zero Point Vibrational Energy (zpe) 16061.4 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(2df,p)
ABC
0.21456 0.19665 0.10261

See section I.F.4 to change rotational constant units
Geometric Data calculated at MP2/6-31G(2df,p)

Point Group is D2h

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
N1 0.000 0.000 1.415
N2 0.000 0.000 -1.415
C3 0.000 1.131 0.697
C4 0.000 -1.131 0.697
C5 0.000 -1.131 -0.697
C6 0.000 1.131 -0.697
H7 0.000 2.063 1.252
H8 0.000 -2.063 1.252
H9 0.000 -2.063 -1.252
H10 0.000 2.063 -1.252

Atom - Atom Distances (Å)
  N1 N2 C3 C4 C5 C6 H7 H8 H9 H10
N12.83091.34021.34022.39592.39592.06982.06983.37243.3724
N22.83092.39592.39591.34021.34023.37243.37242.06982.0698
C31.34022.39592.26212.65681.39331.08523.24233.74192.1602
C41.34022.39592.26211.39332.65683.24231.08522.16023.7419
C52.39591.34022.65681.39332.26213.74192.16021.08523.2423
C62.39591.34021.39332.65682.26212.16023.74193.24231.0852
H72.06983.37241.08523.24233.74192.16024.12664.82702.5042
H82.06983.37243.24231.08522.16023.74194.12662.50424.8270
H93.37242.06983.74192.16021.08523.24234.82702.50424.1266
H103.37242.06982.16023.74193.24231.08522.50424.82704.1266

picture of Pyrazine state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
N1 C3 C6 122.438 N1 C3 H7 116.774
N1 C4 C5 122.438 N1 C4 H8 116.774
N2 C5 C4 122.438 N2 C5 H9 116.774
N2 C6 C3 122.438 N2 C6 H10 116.774
C3 N1 C4 115.125 C3 C6 H10 120.788
C4 C5 H9 120.788 C5 N2 C6 115.125
C5 C4 H8 120.788 C6 C3 H7 120.788
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability