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NH3 Molecule

Optimisation Data

Molecule NH3
Calculation Method RB3LYP
Basis Set 6-31g(d,p)
Final Energy -56.55776863 au
RMS Gradient 0.00000485
Point Group C3V
Bond Distance 1.01798
Bond Angle 105.741
Item               Value     Threshold  Converged?
 Maximum Force            0.000004     0.000450     YES
 RMS     Force            0.000004     0.000300     YES
 Maximum Displacement     0.000072     0.001800     YES
 RMS     Displacement     0.000035     0.001200     YES
 

Diagram

Ammonia

Media:AV4217-NH3OPTIMISATION.LOG

Vibrations

Display Vibration Answers
Questions Answers
modes of vibration 6
degenerate modes 2&3 , 5&6
bending vibrations 4,5,6
bond stretch vibrations 1,2,3
highly symmetric mode 4
umbrella mode 1
experimental bands 4

Charges

Charges
Nitrogen Hydrogen
-1.125 0.375

The nitrogen atom is expected to have a negative charge and the hydrogen atoms are expected to have a positive charge. This is because nitrogen is more electronegative than hydrogen so attracts the electron density towards itself more. Overall the molecule is not charged.

N2 Molecule

Optimisation Data

Molecule N2
Calculation Method RB3LYP
Basis Set 6-31g(d,p)
Final Energy -109.52412868
RMS Gradient 0.00000060
Point Group D*H
Bond Distance 1.10550
Bond Angle 180.00
Item               Value     Threshold  Converged?
 Maximum Force            0.000001     0.000450     YES
 RMS     Force            0.000001     0.000300     YES
 Maximum Displacement     0.000000     0.001800     YES
 RMS     Displacement     0.000000     0.001200     YES

Diagram

nitrogen

Media:AV4217_N2OPTIMISATION.LOG

Vibrations

There is only one vibration, which is the asymmetric stretch as the molecule is linear. There is no dipole moment as the atoms are the same, so the molecule is infrared inactive.

H2 Molecule

Optimisation Data

Molecule H2
Calculation Method RB3LYP
Basis Set 6-31g(d,p)
Final Energy -1.17853936
RMS Gradient 0.00000017
Point Group D*H
Bond Distance 0.74279
Bond Angle 180.00
         Item               Value     Threshold  Converged?
 Maximum Force            0.000000     0.000450     YES
 RMS     Force            0.000000     0.000300     YES
 Maximum Displacement     0.000000     0.001800     YES
 RMS     Displacement     0.000001     0.001200     YES

Diagram

Hydrogen

Media:AV4217-AV4217_H2OPTIMISATION.LOG

Vibrations

The molecule is linear so there is only one vibration (3N-5), which is the assymmetric stretch. It is not infrared active as there is no dipole moment.

Reactivity

Energies

E(NH3) -56.55776863 au
2*E(NH3) -113.1155373 au
E(N2) -109.52412868 au
E(H2) -1.1785393 au
3*E(H2) -3.5356179 au
ΔE -0.05579072 au

ΔE=-146.48kJ/mol

   The ammonia product is more stable, indicated by the negative energy change.

ClF Molecule

Optimisation Data

Molecule ClF
Calculation Method RB3LYP
Basis Set 6-31g(d,p)
Final Energy -559.94269578 au
RMS Gradient 0.00014211
Point Group C*V
Bond Distance 1.66434
Bond Angle 180.00
   Item               Value     Threshold  Converged?
 Maximum Force            0.000246     0.000450     YES
 RMS     Force            0.000246     0.000300     YES
 Maximum Displacement     0.000433     0.001800     YES
 RMS     Displacement     0.000613     0.001200     YES

Diagram

ClF

Media:AV4217_CLFOPTIMISATION.LOG ‎

Vibrations

There is only one stretching vibration since it is a linear molecule. It is infrared active as there is a difference in electronegativities, so there is a dipole moment.

Charges

The charges cancel out overall.

Charges
Chlorine Fluorine
0.309 -0.309

Molecular Orbitals

Orbital 7

This is the molecular orbital formed from the in-phase overlap of the 2s orbital from fluorine and the 3s orbital from chlorine. It forms a σ bonding orbital deep in energy as it is the lowest energy and is occupied. Fluorine is more electronegative so there is greater electron density surrounding it.

Orbital 8

This occupied molecular orbital is formed from the out of phase overlap of the 3s orbital (Cl) and the 2s orbital (F). It forms a σ* antibonding orbital, deep in energy.

Orbital 9

This molecular orbital is formed from the overlap of 2p (F) and 3p (Cl) atomic orbitals. An occupied σ bonding orbital is formed. The antibonding orbital formed form the out of phase overlap of these two atomic orbitals is unoccupied so this moleculao orbital forms a sigma bond between the atoms.

Orbital 10

This a σ bonding orbital formed by the overlap of the 2p (F) and 3p (Cl) orbitals and is occupied.

Orbital 13

This is a σ* antibonding orbital formed from the out of phase overlap of 2p (F) and 3p (Cl) orbital. It is the HOMO of the molecule.

Orbital 14

This is a σ* antibonding orbital that is unoccupied and is the LUMO of the molecule. It is formed by the out of phase over lap of the 2p (F) and 3p (Cl) orbitals.

H2O Molecule

Optimisation Data

Molecule H2O
Calculation Method RB3LYP
Basis Set 6-31g(d,p)
Final Energy -76.41973740 au
RMS Gradient 0.00006276
Point Group C2V
Bond Distance 0.96522
Bond Angle 103.745
         Item               Value     Threshold  Converged?
 Maximum Force            0.000099     0.000450     YES
 RMS     Force            0.000081     0.000300     YES
 Maximum Displacement     0.000115     0.001800     YES
 RMS     Displacement     0.000120     0.001200     YES

Diagram

Water

Media:AV4217_H2OOPTIMISATION.LOG ‎ ‎

Vibrations

Mode Frequency Infrared Vibration
1 1665.00 70.347 Bending
2 3801.05 1.6431 Symmetrical Stretch
3 3914.23 20.2475 Asymmetrical stretch

Charges

Overall the molecule is not charged.

Charges
Hydrogen Oxygen
0.472 -0.944

Molecular Orbitals

Orbital 1

This is a non-bonding orbital formed from the 1s orbital of oxygen and is very deep in energy.

Orbital 2

This is a sigma bonding orbital formed from the in-phase overlap of the 1s orbital from hydrogen and the 2s orbital from oxygen. It is deep in energy.