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All results from a given calculation for HCCN (cyanomethylene)

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 3A"
1 2 no C*V 3Σ
2 1 yes CS 1A'

State 1 (3A") , Conformer 1 (CS)

Jump to S1C2 S2C1 S2C2
Energy calculated at QCISD/3-21G*
 hartrees
Energy at 0K-130.206052
Energy at 298.15K-130.205555
HF Energy-129.955090
Nuclear repulsion energy46.716070
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' 3308 3179 10.10      
2 A' 1820 1749 29.23      
3 A' 1127 1083 6.67      
4 A' 657 631 16.91      
5 A' 439 422 5.29      
6 A" 493 473 1.25      

Unscaled Zero Point Vibrational Energy (zpe) 3921.3 cm-1
Scaled (by 0.9611) Zero Point Vibrational Energy (zpe) 3768.8 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
47.07797 0.35935 0.35663

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 -0.144 -1.244 0.000
C2 0.000 0.091 0.000
N3 0.063 1.297 0.000
H4 0.424 -2.160 0.000

Atom - Atom Distances (Å)
  C1 C2 N3 H4
C11.34222.54881.0779
C21.34221.20762.2900
N32.54881.20763.4752
H41.07792.29003.4752

picture of cyanomethylene state 1 conformation 1
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 N3 176.823 C2 C1 H4 142.019
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability

State 1 (3Σ) , Conformer 2 (C*V)

Jump to S1C1 S2C1 S2C2
Energy calculated at QCISD/3-21G*
 hartrees
Energy at 0K-130.203962
Energy at 298.15K 
HF Energy-129.955932
Nuclear repulsion energy46.861115
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 Σ 3385 3254 43.08      
2 Σ 1642 1578 34.51      
3 Σ 1212 1165 2.86      
4 Π 517 497 1.09      
4 Π 517 497 1.09      
5 Π 311i 299i 52.03      
5 Π 311i 299i 52.03      

Unscaled Zero Point Vibrational Energy (zpe) 3325.0 cm-1
Scaled (by 0.9611) Zero Point Vibrational Energy (zpe) 3195.6 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 QCISD/3-21G*
B
0.35785

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

Point Group is C∞v

Cartesians (Å)
Atom x (Å) y (Å) z (Å)
C1 0.000 0.000 -1.223
C2 0.000 0.000 0.082
N3 0.000 0.000 1.306
H4 0.000 0.000 -2.294

Atom - Atom Distances (Å)
  C1 C2 N3 H4
C11.30502.52981.0707
C21.30501.22482.3757
N32.52981.22483.6004
H41.07072.37573.6004

picture of cyanomethylene state 1 conformation 2
More geometry information
Calculated Bond Angles
atom1 atom2 atom3 angle atom1 atom2 atom3 angle
C1 C2 N3 180.000 C2 C1 H4 180.000
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at QCISD/3-21G* Charges (e)
Number Element Mulliken CHELPG AIM ESP
1 C 0.017      
2 C 0.086      
3 N -0.417      
4 H 0.313      


Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)
  x y z Total
  0.000 0.000 -3.044 3.044
CHELPG        
AIM        
ESP        


Electric Quadrupole moment
Quadrupole components in D Å


Polarizabilities
Components of the polarizability tensor.
Units are Å3 (Angstrom cubed)
Change units.
  x y z
x 0.000 0.000 0.000
y 0.000 0.000 0.000
z 0.000 0.000 0.000


<r2> (average value of r2) Å2
<r2> 36.814
(<r2>)1/2 6.067

State 2 (1A') , Conformer 1 (CS)

Jump to S1C1 S1C2 S2C2
Energy calculated at QCISD/3-21G*
 hartrees
Energy at 0K-130.164237
Energy at 298.15K-130.163760
HF Energy-129.877522
Nuclear repulsion energy46.275684
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' 2946 2832 26.53      
2 A' 2058 1978 40.41      
3 A' 1084 1042 76.38      
4 A' 887 852 2.46      
5 A' 444 427 18.79      
6 A" 415 399 6.44      

Unscaled Zero Point Vibrational Energy (zpe) 3916.9 cm-1
Scaled (by 0.9611) Zero Point Vibrational Energy (zpe) 3764.5 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
17.85866 0.35873 0.35166

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 0.015 -1.310 0.000
C2 0.000 0.101 0.000
N3 -0.164 1.279 0.000
H4 1.058 -1.697 0.000

Atom - Atom Distances (Å)
  C1 C2 N3 H4
C11.41122.59541.1124
C21.41121.18952.0858
N32.59541.18953.2168
H41.11242.08583.2168

picture of cyanomethylene state 2 conformation 1
More geometry information
Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability

State 2 () , Conformer 2 ()

Jump to S1C1 S1C2 S2C1
Energy calculated at QCISD/3-21G*
 hartrees
Energy at 0K-130.164237
Energy at 298.15K-130.163760
HF Energy-129.877522
Nuclear repulsion energy46.275684
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*
Rotational Constants (cm-1) from geometry optimized at QCISD/3-21G*
ABC
17.85866 0.35873 0.35166

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

Point Group is Cs

Electronic energy levels
Charges, Dipole, Quadrupole and Polarizability