Rep:Mod:01389684
NH3 Molecule
test molecule |
Summary Information
| Calculation Method | RB3LYP |
| Basis Set | 6-31G(d.p) |
| Final energy(au) | -56.55776873 |
| RMS Gradient | 0.00000485 |
| Point Group | C3V |
| N-H Bond Length(Angstroms) | 1.01798 |
| H-N-H Bond Angle | 105.741 |
Item table for optimised NH3 Molecule
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
The optimisation file is linked to NH3 Molecule
NH3 Vibrations
From the 3N-6 rule you would expect 6 modes of vibrations for NH3. Modes 2 and 3 are degenerate as well as 5 and 6. Modes 1,2 and 3 are bending vibrations and modes 4,5 and 6 are bond stretching vibrations. Mode 4 is highly symmetric. Mode 1 is the umbrella mode due to the movement of its bending vibrations making it look like an umbrella. 2 bands would be visible in an experimental spectrum of gaseous ammonia despite there being 4 different energy modes as the change in dipole moment in the stretching frequencies (modes 4, 5 and 6) are so small that the intensities of the peaks are very small and so would not be visible in an experimental spectrum especially with noise present.
Charges in the NH3 Molecule
N= -1.125 H= 0.375 This is expected as Nitrogen is more electronegative than Hydrogen and so a more negative charge for Nitrogen would be expected.
N2 Molecule
test molecule |
Summary Information
| Calculation Method | RB3LYP |
| Basis Set | 6-31G(d.p) |
| Final energy(au) | -109.524 |
| RMS Gradient | 0.00000060 |
| Point Group | D*H |
| N-N Bond Length(Angstroms) | 1.10550 |
Item table for optimised N2 Molecule
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
N2 Vibrations
This table shows that Nitrogen would not be infrared active as there is no change in permanent dipole moment.
N2 Molecular Orbitals
| Molecular Orbital | Orbital energy(au) | Description |
|---|---|---|
 |
-14.44676 | This is the molecular orbital of the two core 1s atomic orbitals on each Nitrogen atom. This molecular orbital has the lowest energy as they are held very closely to the nuclei and aren't involved with the chemical bonding. |
 |
-1.12383 | This is the molecular orbital of the two 2s valence atomic orbitals on each Nitrogen atom. These atomic orbitals are involved in chemical bonding as they are much higher in energy and so overlap more strongly. |
 |
-0.55342 | This is the molecular anti bonding orbital of the two 2s valence atomic orbitals on each Nitrogen atom. The energy difference between the bonding and antibonding orbitals between the molecular orbital of the 2s atomic orbitals is much larger than the difference between molecular orbitals of the two 1s atomic orbitals because they overlap better. |
 |
-0.46240 | This is the occupied molecular orbital of two 2p orbitals perpendicular to the bond overlapping to form a pi bond. The molecular orbital is higher in energy. |
H2 Molecule
test molecule |
Summary Information
| Calculation Method | RB3LYP |
| Basis Set | 6-31G(d.p) |
| Final energy(au) | -1.179 |
| RMS Gradient | 0.00000017 |
| Point Group | D*H |
| H-H Bond Length(Angstroms) | 0.74279 |
Item table for optimised H2 Molecule
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
H2 Vibrations
This table shows that Hydrogen will not be infrared active as there is no change in permanent dipole moment.
Energy value for Haber-Bosch Process
| E(NH3) | -56.55776873au |
| 2*E(NH3) | -113.11553750au |
| E(N2) | -109.52412868au |
| E(H2) | -1.17853936au |
| 3*E(H2) | -3.53561808au |
| ΔE | -0.05579070au |
| ΔE | -146.48KJ/mol (2dp) |
The ammonia product is more stable due to it being an exothermic reaction as the ΔE value is -146.48 KJ/mol (2dp) and so the product (ammonia) will have a lower energy than the reactants, making it more stable.
Cl2 Molecule
test molecule |
Summary Information
| Calculation Method | RB3LYP |
| Basis Set | 6-31G(d.p) |
| Final energy(au) | -920.350 |
| RMS Gradient | 0.00002510 |
| Point Group | D*H |
| Cl-Cl Bond Length(Angstroms) | 2.04174 |
Item Table for optimised Cl2 Molecule
Item Value Threshold Converged? Maximum Force 0.000043 0.000450 YES RMS Force 0.000043 0.000300 YES Maximum Displacement 0.000121 0.001800 YES RMS Displacement 0.000172 0.001200 YES
Cl2 Vibrations
This table shows that Cl2 will not be infrared active as there is no change in permanent dipole moment.
Charges on Cl2 Molecule
There are no charges on the chlorine atoms as each atom has the same electronegativity meaning there will be no dipole moment.
Cl2 Molecular Orbitals
| Molecular Orbital | Orbital energy(au) | Description |
|---|---|---|
 |
-9.51828 | This is the occupied bonding molecular orbital resulting from the combination of the 2s atomic orbitals on each chlorine atom. However the two atomic orbitals don't overlap. The molecular orbital is held close to the nuclei and so is deep in energy and is not involved in the chemical bonding. |
 |
-0.93313 | This is the occupied bonding molecular orbital of the two 3s atomic orbital on each chlorine atom. The bonding overlap is so extensive that all we see is one extended surface. The molecular orbital will have a positive effect on the chemical bonding. The energy is much higher compared to the 2s atomic orbitals as the 3s orbitals are further away from the respective nuclei. |
 |
-0.47392 | This is the sigma bonding molecular orbital of two valence 3p atomic orbitals on each chlorine atom. The molecular orbital is occupied due to the overlap of the two 3p atomic orbitals. The molecular orbital has a positive effect on the chemical bonding. The molecular orbital is high in energy. |
 |
-0.40695 | This is the pi system resulting from the overlap of the perpendicular 3p orbitals on each chlorine atom making it an occupied orbital. The molecular orbital will have a positive effect on the chemical bonding. Since there are two 3p orbitals not involved in the sigma bond on each chlorine atom there is another degenerate pi system molecular orbital.The molecular orbital is high in energy. |
 |
-0.31361 | This is the occupied antibonding molecular orbital of the 3p orbitals on each chlorine atom. The molecular orbital is involved in chemical bonding however it has a negative effect on the bonding as it weakens the chemical bond. The energy is near the HOMO/LUMO region. |