Marshaluke
Contents
NH3 Molecule
Calculation Data
| Log file name | LAM_OPT_NH3_POP.LOG |
| Molecule | NH3 |
| Method | RB3LYP |
| Basis Set | 6-31G(d,p) |
| Final Energy | -56.557769 |
| RMS Gradient | 1.53e-07 |
| Point Group | C3v |
Item Table
Item Value Threshold Converged?
Maximum Force 0.000000 0.000015 YES
RMS Force 0.000000 0.000010 YES
Maximum Displacement 0.000003 0.000060 YES
RMS Displacement 0.000001 0.000040 YES
Low Frequencies-- -5.6864, -3.6131, -3.6124, -0.0008, 0.0047, 0.0163 Low Frequencies-- 1089.3674, 1693.9284, 1693.9284
Optimised Structure Image
Jmol Rotateable Structure
logfile: Media:LAM_OPT_NH3_POP.LOG
Optimised NH Molecule |
Important Geometric Parameters
Optimised bond angle and distance for NH3
| Coord | Value |
| r(N-H) | 1.02Å |
| θ | 106° |
Vibrations
Table of vibrations:
| Mode | 1 | 2 | 3 | 4 | 5 | 6 |
| Wavenumber(cm-1) | 1089.37 | 1693.93 | 1693.93 | 3461.38 | 3589.93 | 3589.93 |
| Symmetry | A1 | E | E | A1 | E | E |
| Intensity(arbitrary units) | 145 | 14 | 14 | 1 | 0 | 0 |
Gaussian copy of IR spectra:
Questions and Answers
Charges
Image of NBO charges colour coded, red for negative, green for positive. Next to it is the scale and reference for the charge distribution. The scale is -1.125 to 1.125
Table of NH3 charges:
| Atom | Charge |
| N | -1.13 |
| H | 0.38 |
Molecular Orbitals
| Real 2A1 Orbital | LCAO Orbital |
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Project Molecule
Calculation Data
| Log file name | LAM_N2F2_OPT_POP.LOG |
| Molecule | N2F2 |
| Method | RB3LYP |
| Basis Set | 6-31G(d,p) |
| Final Energy | -309.012413 |
| RMS Gradient | 0.000004 |
| Point Group | C2v |
Item Table
Item Value Threshold Converged?
Maximum Force 0.000011 0.000015 YES
RMS Force 0.000006 0.000010 YES
Maximum Displacement 0.000025 0.000060 YES
RMS Displacement 0.000015 0.000040 YES
Low Frequencies-- -1.0715, -0.0014, -0.0011, -0.0009, 2.6488, 5.3711 Low Frequencies-- 347.8610, 561.2419, 771.5834
Optimised Structure Image
Jmol Rotateable Structure
logfile: Media:LAM_OPT_NH3_POP.LOG
Optimised NF Molecule |
Important Geometric Parameters
Optimised bond angle and distance for N2F2
| Coord | Value |
| r(N-H) | 1.02Å |
| θ | 106° |
Vibrations
Table of vibrations:
| Mode | 1 | 2 | 3 | 4 | 5 | 6 |
| Wavenumber(cm-1) | 1089.37 | 1693.93 | 1693.93 | 3461.38 | 3589.93 | 3589.93 |
| Symmetry | A1 | E | E | A1 | E | E |
| Intensity(arbitrary units) | 145 | 14 | 14 | 1 | 0 | 0 |
Gaussian copy of IR spectra:
Questions and Answers
1. how many modes do you expect from the 3N-6 rule? With N being the no. of atoms present, this being 4 in this case. Means that the modes of this molecule would be equal to (3x4)-6 = 6. Suggesting correctly that there are 6 modes
2. how many bands (peaks) do you see in the computed spectrum of gaseous ammonia? There are only two bands present as the other modes have little to no intensity
3. which modes are degenerate (ie have the same energy)? Modes 2 & 3, as well as 5 & 6 are degenerate.
4. which modes have essentially no intensity? Modes 4-6 have intensities lesser than 2 which renders them insignificant on the spectrum
5. why are there fewer modes in the spectrum than you would predict from the 3N-6 rule? Because the degeneracy of some of them cause them to overlap and intensify as well as some of them not being intense enough to visualise
6. which modes are "bending" vibrations and which are "bond stretch" vibrations? 1-3 are bending vibrations, while 4-6 are stretching vibrations as stretching is high energy and rare.
7. one mode is known as the "umbrella" mode, which one is this? This is mode 1 as it's vibration looks similar to that of an umbrella caught in wind and at normal state.
8. why is the umbrella mode so intense? It causes a large dipole moment change
Charges
Image of NBO charges colour coded, red for negative, green for positive. Next to it is the scale and reference for the charge distribution. The scale is -1.125 to 1.125
Table of NH3 charges:
| Atom | Charge |
| N | -1.13 |
| H | 0.38 |
Molecular Orbitals
| Real 2A1 Orbital | LCAO Orbital |
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