Milmindani

BH₃ Molecule

calculation data

name of submitted log file	BH3 Optimisation DM.log
molecule	BH3
method	B3LYP
calculation method	RB3LYP
basis set	6-31G(d,p)
final energy	-26.615324
RMS gradient	0.000002
point group	D3H
Confirmed it is Minima	Yes

Media:BH3_Optimisation_Log_File.log.log

rotateable 3D Jmol image BH

Item Table

 Item               Value     Threshold  Converged?
 Maximum Force            0.000004     0.000015     YES
 RMS     Force            0.000003     0.000010     YES
 Maximum Displacement     0.000017     0.000060     YES
 RMS     Displacement     0.000011     0.000040     YES

Important geometric parameters

Optimised bond distance and angle for BH₃
Bond Distance: r(N-F)=1.19200Â
Bond Angle (N-F): 120°
Low frequencies --- -11.6940 -11.6861 -6.5543 -0.0002 0.0280 0.4289
Low frequencies --- 1162.9745 1213.1390 1213.1392

Mode	1	2	3	4	5	6
wavenumber (cm-1)	1162.9745	1213.1390	1213.1392	2582.5813	2715.7180	2715.7189
Symmetry	A2"	E'	E'	A1'	E'	E'
intensity (arbitrary units)	92.5282	14.0550	14.0544	0.0000	126.3320	126.3260

NH₃BH₃ Molecule

calculation data

name of submitted log file	NH3BH3_Optimisation_Log_File.log.log
molecule	NH3BH3
method	B3LYP
calculation method	RB3LYP
basis set	6-31G(d,p)
final energy	-83.224689
RMS gradient	0.000001
point group	C1
Confirmed it is Minima	Yes

Media:NH3BH3_Optimisation_Log_File.log.log

rotateable 3D Jmol image BH

Item Table

 Item               Value     Threshold  Converged?
 Maximum Force            0.000002     0.000015     YES
 RMS     Force            0.000001     0.000010     YES
 Maximum Displacement     0.000041     0.000060     YES
 RMS     Displacement     0.000020     0.000040     YES

Important geometric parameters

Optimised bond distance and angle for BH₃
Bond Distance: r(N-H)=1.01847Â
Bond Distance: r(B-H)=1.20977Â
Bond Distance: r(B-N)=1.66771Â

Bond Angle (N-H): 107.88°
Bond Angle (B-H): 113.88°

Low frequencies ---   -3.6199   -0.0014   -0.0010   -0.0009    2.3908    4.5604
Low frequencies ---  263.4365  632.9747  638.4332

Mode	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
wavenumber (cm-1)	263.4365	632.9747	638.4332	638.5054	1069.1617	1196.1866	1203.5225	1203.5771	1328.8170	1676.0434	1676.0577	2471.9811	2532.0716	2532.0950	3464.1021	3581.1459	3581.1541
Symmetry	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A
intensity (arbitrary units)	0.0000	14.0108	3.5475	3.5464	40.5051	40.5105	108.9677	3.4694	3.4694	113.6226	27.5645	27.5669	67.2027	231.2478	2.5113	27.9556	27.9571	} NH3 Molecule calculation data name of submitted log file NH3 Optimisation DM.log molecule NH3 method RB3LYP basis set 6-31G(d,p) final energy -56.557769 RMS gradient 0.000000 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 Media:BH3_Optimisation_Log_File.log.log rotateable 3D Jmol image NH Important geometric parameters Optimised bond distance and angle for NH3 Bond Distance: r(N-H)=1.01797Â Bond Angle: 37.12783° Low frequencies --- -5.6864 -3.6131 -3.6124 0.0017 0.0048 0.0162 Low frequencies --- 1089.3674 1693.9284 1693.9284 Mode 1 2 3 4 5 6 wavenumber (cm-1) 1089.3674 1693.9284 1693.9284 3461.3788 3589.9285 3589.9285 Symmetry A1 E E A1 E E intensity (arbitrary units) 145.4277 13.5571 13.5572 1.0593 0.2699 0.2699 Charges N-Atom H-Atom H-Atom H-Atom Charge -1.125 0.375 0.375 0.375 Project Molecule N2F2 calculation data name of submitted log file N2F2 MOLECULE 1 DM.log molecule N2F2 method RB3LYP basis set 6-31G(d,p) final energy -309.012413 RMS gradient 0.000000 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 Media:N2F2 MOLECULE 1 DM.LOG rotateable 3D Jmol image Nf Important geometric parameters Optimised bond distance and angle for NH3 Bond Distance: r(N-F)=1.28000Â Bond Distance: r(N=N)=1.23200Â Bond Angle (N-F): 120° Low frequencies --- 0.0013 0.0015 0.0017 3.2233 4.3533 5.0998 Low frequencies --- 347.8772 561.2472 771.6105 Mode 1 2 3 4 5 6 wavenumber (cm-1) 347.8772 561.2472 771.6105 949.4548 987.2543 1636.6075 Symmetry A1 A2 B2 A1 B2 A1 intensity (arbitrary units) 0.6108 0.0000 74.7044 75.4125 81.1265 20.5391 Charges N-Atom F-Atom N-Atom F-Atom Charge 0.191 -0.191 0.191 -0.191 Questions: the molecule from the log file does not have bonds between the F and N atoms, what is going on here? It does have bonds, you just need to change the number from 8 to 1 or 2 to see where the animation connects the bond together. IR analysis how many vibrations are expected from the 3N-6 rule? The 3N-6 rule, calculates the number of vibrational modes in the molecule where N=the total number of atoms. As N2F2 has 4 atoms, N=4. So 3*(4)-6 = 6 vibrational modes are present in N2F2. why are there only 4 peaks in the IR spectrum? The molecule is symmetrical so although there are 6 vibrational modes, only 4 modes are visible because the symmetry of the molecule cancels dipole so they do not show up in an IR spectrum. which vibration is the asymmetric N-F stretch? The vibration at 775 cm-1 is the asymmetric N-F stretch. what is the nature of the highest energy vibration? This is the N=N stretch located at 1640 cm-1. The peak is small which is due to the tight N=N bond not moving that much. MO analysis: which MOs are core orbital MOs? The 1S orbitals of both F atoms and the 1s orbitals of both N atoms. MO's 1-4. provide a picture of MO 9 and beside it draw the LCAO diagram Lab1 Marking It's good that you have a working wiki. However, your reported image and charges of N2F2 do not correspond to an optimised structure. 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.