User:Jefferalan

Lab1 Marking

You did a great job especially with the formatting. However, a wavenumber was rounded incorrectly, and you have missed to include the low frequencies, torsion angle, and NN bond distance. Don't forget to consider the accuracy to which you report your data the next time. If you have any queries, please contact Prof. Hunt.

NH₃ Molecule

Calculation data

name of submitted log file	ACJefferys_nh3_optf.log
molecule	NH3
method	RB3LYP
basis set	6-31G(d,p)
final energy	-56.557769
RMS gradient	0.000000153
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

Optimised molecule image

Jmol rotatable molecule

logfile: Media:ACJEFFERYS_NH3_OPTF_POP.LOG

Optimised NH Molecule

Important geometric parameters

Optimised bond distance and angle for NH₃
r(N-H)=1.02Â
θ(H-N-H)=106°

Vibrations

Mode	1	2	3	4	5	6
Wavenumber(cm-1)	1089	1694	1694	3461	3590	3590
Symmetry	A1	E	E	A1	E	E
Intensity(arbitary units)	145	14	14	1	0	0

Charge analysis image

NH₃ Charges

N-atom	H-atom
-1.125	0.375

Project Molecule

Calculation data

name of submitted log file	ACJefferys_n2f2_optf.log
molecule	N2F2
method	RB3LYP
basis set	6-31G(d,p)
final energy	-309.01241
RMS gradient	0.000000317
point group	C2V

Item Table

   Item               Value     Threshold  Converged?
 Maximum Force            0.000001     0.000015     YES
 RMS     Force            0.000000     0.000010     YES
 Maximum Displacement     0.000001     0.000060     YES
 RMS     Displacement     0.000001     0.000040     YES

Optimised molecule image

Jmol rotatable molecule

logfile: Media:ACJEFFERYS_N2F2_OPTF.LOG

Optimised NF Molecule

Important geometric parameters

Optimised bond distance and angle for NH₃
r(N-F)=1.39Â
θ(F-N-N)=114°

Vibrations

Mode	1	2	3	4	5	6
Wavenumber(cm-1)	348	561	772	949	988	1637
Symmetry	A1	A2	B2	A2	B2	A1
Intensity(arbitary units)	1	0	75	75	81	21

Charge analysis image

NH₃ Charges

N-atom	F-atom
0.215	-0.215

IR Analysis

According to the 3N-6 rule, as there are 4 atoms in N₂F₂, it is expected that there will be 6 vibrational modes. However, the IR spectrum shows only 4 strong bands at 772, 950, 987 and 1637 cm-1. The vibrational mode at 348 cm-1 (A1) is most likely too low to be detected, and the vibration at 561 cm-1 (A2, out of plane bending) is most likely IR inactive as it doesn't change the molecular dipole movement. The vibration at 772 cm-1, mode 3, is the asymmetric N-F stretching. The highest energy vibration at 1637 cm-1, mode 6, is the N=N stretching.

MO Analysis

The core MOs on N₂F₂ are 1, 2, 3 and 4