return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Calculated > Energy > Optimized > Energy

All results from a given calculation for HCCO (ketenyl radical)

using model chemistry: PM3

19 10 17 12 22

States and conformations

State Conformation minimum conformation conformer description state description

Conformer 1 (C*V)

Jump to S1C2
Energy calculated at PM3
 hartrees
Energy at 0K 
Energy at 298.15K0.057925
HF Energy0.057925
Nuclear repulsion energy41.321628
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 PM3
Mode Number Symmetry Frequency
(cm-1)
Scaled Frequency
(cm-1)
IR Intensities
(km mol-1)
Raman Act
4/u)
Dep P Dep U
1 Σ 3333 3247 190.53 21.87 0.35 0.52
2 Σ 2064 2011 266.52 2.83 0.11 0.20
3 Σ 1371 1335 29.94 34.44 0.25 0.40
4 Π 510 496 76.35 6.88 0.75 0.86
4 Π 501 488 68.36 5.00 0.75 0.86
5 Π 442 430 5.91 0.08 0.75 0.86
5 Π 369 359 108.51 30.25 0.75 0.86

Unscaled Zero Point Vibrational Energy (zpe) 4294.7 cm-1
Scaled (by 0.974) Zero Point Vibrational Energy (zpe) 4183.1 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 PM3
B
0.35551

See section I.F.4 to change rotational constant units
Geometric Data calculated at PM3

Point Group is C∞v

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 0.000 0.018
C2 0.000 0.000 -1.248
O3 0.000 0.000 1.211
H4 0.000 0.000 -2.311

Atom - Atom Distances (Å)
  C1 C2 O3 H4
C11.26591.19342.3293
C21.26592.45931.0635
O31.19342.45933.5227
H42.32931.06353.5227

picture of ketenyl radical state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 H4 180.000 C2 C1 O3 180.000
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability

Conformer 2 (CS)

Jump to S1C1
Energy calculated at PM3
 hartrees
Energy at 0K 
Energy at 298.15K0.057925
HF Energy0.057925
Nuclear repulsion energy41.321927
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 PM3
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' 3333 3247 190.54 21.87 0.35 0.52
2 A' 2065 2011 266.61 2.83 0.11 0.20
3 A' 1371 1335 29.94 34.44 0.25 0.40
4 A' 501 488 68.39 5.00 0.75 0.86
5 A' 369 359 108.50 30.24 0.75 0.86
6 A" 488 475 72.64 5.28 0.75 0.86

Unscaled Zero Point Vibrational Energy (zpe) 4063.0 cm-1
Scaled (by 0.974) Zero Point Vibrational Energy (zpe) 3957.4 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 PM3
B
0.35552

See section I.F.4 to change rotational constant units
Geometric Data calculated at PM3

Point Group is Cs

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 -0.018 0.000
C2 -0.005 1.248 0.000
O3 0.005 -1.211 0.000
H4 -0.009 2.311 0.000

Atom - Atom Distances (Å)
  C1 C2 O3 H4
C11.26581.19342.3293
C21.26582.45921.0634
O31.19342.45923.5227
H42.32931.06343.5227

picture of ketenyl radical state 1 conformation 2
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 H4 179.998 C2 C1 O3 179.991
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability