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All results from a given calculation for CH3CHO (Acetaldehyde)

using model chemistry: QCISD/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 QCISD/3-21G
 hartrees
Energy at 0K-152.384578
Energy at 298.15K 
HF Energy-152.052011
Nuclear repulsion energy68.386244
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 QCISD/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' 3132 3036 10.81      
2 A' 3030 2936 2.61      
3 A' 2916 2826 115.14      
4 A' 1691 1639 55.84      
5 A' 1542 1495 19.66      
6 A' 1461 1416 3.39      
7 A' 1447 1402 25.38      
8 A' 1133 1098 24.43      
9 A' 867 841 11.08      
10 A' 489 474 10.77      
11 A" 3087 2992 9.59      
12 A" 1556 1508 10.90      
13 A" 1164 1128 0.59      
14 A" 818 793 1.81      
15 A" 164 159 0.37      

Unscaled Zero Point Vibrational Energy (zpe) 12249.2 cm-1
Scaled (by 0.9692) Zero Point Vibrational Energy (zpe) 11871.9 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 QCISD/3-21G
ABC
1.85837 0.32414 0.29124

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

Point Group is Cs

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 0.471 0.000
C2 -0.967 -0.715 0.000
O3 1.240 0.375 0.000
H4 -0.503 1.458 0.000
H5 -0.394 -1.650 0.000
H6 -1.612 -0.671 0.890
H7 -1.612 -0.671 -0.890

Atom - Atom Distances (Å)
  C1 C2 O3 H4 H5 H6 H7
C11.53011.24401.10782.15652.16642.1664
C21.53012.46192.22211.09601.10041.1004
O31.24402.46192.05192.60203.16563.1656
H41.10782.22212.05193.10932.56002.5600
H52.15651.09602.60203.10931.79841.7984
H62.16641.10043.16562.56001.79841.7810
H72.16641.10043.16562.56001.79841.7810

picture of Acetaldehyde state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 H5 109.289 C1 C2 H6 109.813
C1 C2 H7 109.813 C2 C1 O3 124.789
C2 C1 H4 113.823 O3 C1 H4 121.389
H5 C2 H6 109.931 H5 C2 H7 109.931
H6 C2 H7 108.049
Electronic energy levels

Electronic state

Charges, Dipole, Quadrupole and Polarizability