Difference between revisions of "Wolfeka"
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===Questions and answers=== | ===Questions and answers=== | ||
| − | 1. The molecule from the log file does not have bonds between the F and N atoms, what is going on here? | + | <b>1. The molecule from the log file does not have bonds between the F and N atoms, what is going on here?</b> |
The program running the optimization works under an assumption of what the length of the F and N atoms should be, and since the optimization put their bond length as longer than this assumed value, the program did not include a bond there. As the atoms get closer the program will include a bond between the atoms. | The program running the optimization works under an assumption of what the length of the F and N atoms should be, and since the optimization put their bond length as longer than this assumed value, the program did not include a bond there. As the atoms get closer the program will include a bond between the atoms. | ||
| − | 2. For your IR analysis how many vibrations are expected from the 3N-6 rule? | + | <b>2. For your IR analysis how many vibrations are expected from the 3N-6 rule?</b> |
3N-6 where N is the number of atoms would give N=4 and 3(4)-6= 6 vibrational modes, this is consistent with the number of vibrational modes obtained in the optimization as well. | 3N-6 where N is the number of atoms would give N=4 and 3(4)-6= 6 vibrational modes, this is consistent with the number of vibrational modes obtained in the optimization as well. | ||
| − | 3. Why are there only 4 peaks in the IR spectrum? | + | <b>3. Why are there only 4 peaks in the IR spectrum?</b> |
| − | The A1 vibrational mode at and the | + | The A1 vibrational mode at 348 cm<sup>-1</sup> and the A2 vibrational mode at 561 cm<sup>-1</sup> both have an intensity of close to zero and were not detected by the IR |
| − | 4. For your IR analysis which vibration is the asymmetric N-F stretch? | + | <b>4. For your IR analysis which vibration is the asymmetric N-F stretch?</b> |
| − | 5. For your IR analysis what is the nature of the highest energy vibration? | + | |
| + | Vibrational mode 3 | ||
| + | |||
| + | <b>5. For your IR analysis what is the nature of the highest energy vibration?</b> | ||
| + | |||
| + | Symmetrical N-N bond stretching, vibrational mode 6 | ||
Revision as of 01:28, 2 April 2026
Contents
NH3 molecule
Calculation data
| name of submitted log file | KATW307_nh3opt1.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 0.000002 0.000015 YES RMS Force 0.000001 0.000010 YES Maximum Displacement 0.000010 0.000060 YES RMS Displacement 0.000006 0.000040 YES
Key bond distances and angles
| r(N-H) bond distance | 1.02Â |
| θ(H-N-H) bond angle | 106° |
Optimised molecule image
File history
3D NH molecule |
Low frequencies --- -5.6864 -3.6131 -3.6124 0.0022 0.0047 0.0163 Low frequencies --- 1089.3674 1693.9284 1693.9284
| mode | 1 | 2 | 3 | 4 | 5 | |
| wavenumber (cm-1) | 1089 | 1694 | 1694 | 3461 | 3590 | 3590 |
| symmetry | A1 | E | E | A1 | E | E |
| intensity | 145 | 14 | 14 | 1 | 0 | 0 |
NH3 charges
| Atom | Charge (e) |
| N | -1.13 |
| H3 | 0.38 |
NH3 IR spectrum
Project molecule
Calculation data
| name of submitted log file | KATW307_n2f2opt1.log |
| molecule | N2F2 |
| method | RB3LYP |
| basis set | 6-31G(d,p) |
| final energy | -309.0124 |
| RMS gradient | 1.218e-06 |
| point group | C2v |
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
Key bond distances and angles
| r(N-N) bond distance | 1.22Â |
| r(N-F) bond distance | 1.39Â |
| θ(N-N-F) bond angle | 114° |
Optimised molecule image
File history
N2F2 frequencies
3D NH molecule |
Low frequencies --- -0.0011 0.0008 0.0019 3.4929 4.3715 5.1621 Low frequencies --- 347.8732 561.2460 771.6039
| mode | 1 | 2 | 3 | 4 | 5 | 6 |
| wavenumber (cm-1) | 348 | 561 | 772 | 949 | 987 | 1637 |
| symmetry | A1 | A2 | B2 | A1 | B2 | A1 |
| intensity (arbitrary units) | 1 | 0 | 75 | 75 | 81 | 21 |
N2F2 charges
| Atom | Charge (e) |
| N2 | 0.22 |
| F2 | -0.22 |
N2F2 IR spectrum
Questions and answers
1. The molecule from the log file does not have bonds between the F and N atoms, what is going on here?
The program running the optimization works under an assumption of what the length of the F and N atoms should be, and since the optimization put their bond length as longer than this assumed value, the program did not include a bond there. As the atoms get closer the program will include a bond between the atoms.
2. For your IR analysis how many vibrations are expected from the 3N-6 rule?
3N-6 where N is the number of atoms would give N=4 and 3(4)-6= 6 vibrational modes, this is consistent with the number of vibrational modes obtained in the optimization as well.
3. Why are there only 4 peaks in the IR spectrum?
The A1 vibrational mode at 348 cm-1 and the A2 vibrational mode at 561 cm-1 both have an intensity of close to zero and were not detected by the IR
4. For your IR analysis which vibration is the asymmetric N-F stretch?
Vibrational mode 3
5. For your IR analysis what is the nature of the highest energy vibration?
Symmetrical N-N bond stretching, vibrational mode 6
