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All results from a given calculation for C4H6O2 (Crotonic Acid)

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 CS 1A'
Energy calculated at MP2/3-21G*
 hartrees
Energy at 0K-303.588012
Energy at 298.15K-303.594693
HF Energy-302.987358
Nuclear repulsion energy217.512215
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 A' 3520 3348 28.50      
2 A' 3218 3062 5.65      
3 A' 3211 3055 0.07      
4 A' 3153 3000 13.02      
5 A' 3076 2926 11.50      
6 A' 1753 1668 116.20      
7 A' 1690 1607 34.51      
8 A' 1590 1512 8.19      
9 A' 1495 1422 6.98      
10 A' 1404 1335 36.69      
11 A' 1374 1307 10.61      
12 A' 1350 1285 0.17      
13 A' 1179 1122 109.52      
14 A' 1094 1041 147.38      
15 A' 983 935 14.48      
16 A' 857 815 31.19      
17 A' 617 587 52.54      
18 A' 491 467 2.08      
19 A' 395 376 3.67      
20 A' 206 196 0.30      
21 A" 3137 2985 13.74      
22 A" 1583 1506 7.98      
23 A" 1138 1083 0.02      
24 A" 1034 984 47.06      
25 A" 865 823 8.41      
26 A" 685 651 48.18      
27 A" 573 545 125.30      
28 A" 207 197 0.48      
29 A" 192 183 0.72      
30 A" 110 104 0.89      

Unscaled Zero Point Vibrational Energy (zpe) 21090.3 cm-1
Scaled (by 0.9513) Zero Point Vibrational Energy (zpe) 20063.2 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 MP2/3-21G*
ABC
0.31738 0.06390 0.05372

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

Point Group is Cs

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 -1.117 -0.342 0.000
C2 0.000 0.634 0.000
C3 1.292 0.266 0.000
C4 2.454 1.238 0.000
O5 -0.650 -1.663 0.000
O6 -2.326 -0.068 0.000
H7 -0.304 1.677 0.000
H8 1.530 -0.794 0.000
H9 2.097 2.273 0.000
H10 3.083 1.084 0.885
H11 3.083 1.084 -0.885
H12 -1.449 -2.256 0.000

Atom - Atom Distances (Å)
  C1 C2 C3 C4 O5 O6 H7 H8 H9 H10 H11 H12
C11.48292.48423.90461.40141.23942.17582.68584.14384.52244.52241.9433
C21.48291.34272.52722.38682.42931.08632.09302.66233.23863.23863.2329
C32.48421.34271.51482.73733.63282.12931.08722.16282.15862.15863.7249
C43.90462.52721.51484.24854.95482.79252.23201.09541.09671.09675.2385
O51.40142.38682.73734.24852.31363.35742.34724.80054.71824.71820.9951
O61.23942.42933.63284.95482.31362.67033.92405.00455.60005.60002.3578
H72.17581.08632.12932.79253.35742.67033.07722.47443.55013.55014.0962
H82.68582.09301.08722.23202.34723.92403.07723.11972.59222.59223.3188
H94.14382.66232.16281.09544.80055.00452.47443.11971.78051.78055.7530
H104.52243.23862.15861.09674.71825.60003.55012.59221.78051.77065.6987
H114.52243.23862.15861.09674.71825.60003.55012.59221.78051.77065.6987
H121.94333.23293.72495.23850.99512.35784.09623.31885.75305.69875.6987

picture of Crotonic Acid state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 C3 123.007 C1 C2 H7 114.873
C1 O5 H12 107.146 C2 C1 O5 111.660
C2 C1 O6 126.110 C2 C3 C4 124.242
C2 C3 H8 118.562 C3 C2 H7 122.121
C3 C4 H9 110.888 C3 C4 H10 110.473
C3 C4 H11 110.473 C4 C3 H8 117.195
O5 C1 O6 122.230 H9 C4 H10 108.629
H9 C4 H11 108.629 H10 C4 H11 107.659
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability