Y2inorg js2016

2018-05-18T13:15:32Z

Js2016: /* MO comparison */

== Example data set ==
=== BH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000203 0.000450 YES
RMS Force 0.000098 0.000300 YES
Maximum Displacement 0.000867 0.001800 YES
RMS Displacement 0.000415 0.001200 YES

Frequency analysis log file [[Media:JS2016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -0.2263 -0.1037 -0.0054 47.9770 49.0378 49.0383
Low frequencies --- 1163.7209 1213.6704 1213.6731
</pre>

<jmol><jmolApplet>
<title>optimised BH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Optimised BH3 vibrational analysis
! Mode # !! Frequency (cm-1) !! Infrared !! IR active? !! Vibration type
|-
| 1 || 1164 || 92 || Yes || Bond angle deformation
|-
| 2 || 1214 || 14 || Yes || Bond angle deformation
|-
| 3 || 1214 || 14 || Yes || Bond angle deformation
|-
| 4 || 2580 || 0 || No || Bond stretch
|-
| 5 || 2713 || 126 || Yes || Bond stretch
|-
| 6 || 2713 || 126 || Yes || Bond stretch
|}

==== IR spectrum of BH3 ====
[[File:BH3_FREQ_VT_js2016.png]]

Although the vibrational analysis clearly shows 6 modes of vibration, there are fewer peaks shown in the IR spectrum. This is because one mode (#4) has no intensity and there are two different degenerate pairs of vibrations, one set being a bond angle deformation (modes 2 and 3) and the other a bond stretching (modes 5 and 6). Hence there is no signal for mode 4 and one peak shown for modes 2 and 3, and one peak shown for modes 5 and 6. In total, only 3 peaks appear in the IR spectrum.

==== MO diagram of BH3 ====

[[File:BH3_MOdiagram_js2016.png|BH3_MOdiagram_js2016.png]]

The LCAO of MOs show a great deal of similarity with the "real" MOs obtained from Gaussian as seen from the MO diagram.<ref name="1st"/> There are slight differences i.e. with MOs a``2 and a`1. However, one can accurately predict the "real" MOs with good confidence using qualitative MO theory.

=== NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000012 0.001800 YES
RMS Displacement 0.000008 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000122 0.000450 YES
RMS Force 0.000058 0.000300 YES
Maximum Displacement 0.000513 0.001800 YES
RMS Displacement 0.000296 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3BH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3BH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3-NH3 association energies ===

<pre>
E(NH3) = -56.55776873 au
E(BH3) = -26.61532342 au
E(NH3BH3) = -83.22468888 au

ΔE = [E(NH3)+E(BH3)] + E(NH3BH3)
ΔE = 0.05159673 au = 135 kJ/mol
</pre>

The B-N dative bond is weak with a dissociation energy of 135 kJ/mol, significantly lower than the C-I bond (213 kJ/mol) which is another comparatively weak bond.<ref name="2nd" />

=== BBr3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BBR3_OPT_GEN_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000015 0.000450 YES
RMS Force 0.000009 0.000300 YES
Maximum Displacement 0.000058 0.001800 YES
RMS Displacement 0.000042 0.001200 YES

Frequency analysis log file [[Media:JS2016_BBR3_FREQ_GEN.log]]

<pre>
Low frequencies --- -4.3191 -2.7656 -2.2989 -0.0002 -0.0001 0.0002
Low frequencies --- 155.8708 155.9430 267.6975
</pre>

<jmol><jmolApplet>
<title>optimised BBr3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BBR3_FREQ_GEN.log</uploadedFileContents>
</jmolApplet></jmol>

Link: http://hdl.handle.net/10042/202424

{{DOI|10042/202424}}

<references>
<ref name="1st">MO diagram used is from tutorial sheet of Patricia Hunt.</ref>
<ref name="2nd">https://ch301.cm.utexas.edu/section2.php?target=thermo/thermochemistry/enthalpy-bonds.html</ref>
</references>

== Aromaticity ==

=== Benzene ===
'''B3LYP/6-31G(d,p) level'''

[[File:BENZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000198 0.000450 YES
RMS Force 0.000082 0.000300 YES
Maximum Displacement 0.000849 0.001800 YES
RMS Displacement 0.000305 0.001200 YES

Frequency analysis log file [[Media:JS2016_BENZ_FREQ.LOG]]

<pre>
Low frequencies --- -11.6728 -0.0004 0.0007 0.0009 6.6686 15.6846
Low frequencies --- 414.0392 414.6031 621.0860
</pre>

<jmol><jmolApplet>
<title>Optimised Benzene molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BENZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== Borazine ===
'''B3LYP/6-31G(d,p) level'''

[[File:BORAZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000085 0.000450 YES
RMS Force 0.000033 0.000300 YES
Maximum Displacement 0.000249 0.001800 YES
RMS Displacement 0.000077 0.001200 YES

Frequency analysis log file [[Media:JS2016_BORAZ_FREQ.LOG]]

<pre>
Low frequencies --- -17.8308 -12.6833 -9.1489 -0.0008 -0.0006 0.0012
Low frequencies --- 289.0049 289.4700 404.2277
</pre>

<jmol><jmolApplet>
<title>Optimised Borazine molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BORAZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== NBO charge analysis ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! Benzene !! Borazine
|-
| [[File:BENZ_CD.png]] || [[File:BORAZ_CD.png]]
|}

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! !! Benzene !! !! Borazine
|-
| Carbon || -0.24 || Nitrogen || -1.102
|-
| Hydrogen || 0.24 || Boron || 0.747
|-
| || || Hydrogen (N-H) || 0.432
|-
| || || Hydrogen (B-H) || -0.077
|}

The charge distribution diagram of benzene illustrates that most of the electron density is localized on the pi ring system. The point group of benzene is D6h which corresponds to a charge of -0.24 on all the carbon atoms and a charge of 0.24 on all the hydrogen atoms as shown. Borazine, on the other hand, has a rather more complex charge distribution. The nitrogen atoms have the most negative charge (-1.102) so most of the electron density will be found at and very close to these nitrogen atoms. The neighbouring atoms to nitrogen as a result have positive charges, where boron has a charge of 0.747 and hydrogen (B-H) has a charge of 0.432. Lastly, the hydrogen atoms bonded to boron have a charge of -0.077. Albeit a small negative charge, these hydrogen atoms have retained electron density because of their distance from the electronegative nitrogen atoms.

=== MO comparison ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! MO # !! MO in benzene !! MO # !! MO in borazine !! Description
|-
| 8 || [[File:BENZ_MO8.png]] || 8 || [[File:BORAZ_MO8.png]] || This MO has the second lowest in energy bonding MO in both complexes. MO 8 in benzene has significant symmetry with one half of the molecule (3 consecutive C-H units on the ring) in phase and the other out of phase. MO 8 in borazine has less symmetry due to electron density being drawn to the nitrogen atoms, causing very little contribution from some of the hydrogen atoms.
|-
| 13 || [[File:BENZ_MO13.PNG]] || 16 || [[File:BORAZ_MO16.PNG]] || Both of these MOs exhibit anti-bonding character with orbital lobes focused onto one ring atom (C/B/N) and one hydrogen atom. Again the MO in benzene has a high degree of symmetry and the MO in borazine has significant distortions. However, the boron orbitals are higher in energy and therefore must contribute more to these anti-bonding orbitals. This is why larger lobes are present around the boron atoms.
|-
| 20 || [[File:BENZ_MO20.PNG]] || 20 || [[File:BORAZ_MO20.PNG]] || The MOs in both benzene and borazine are bonding π orbitals. Distortion of the electron density can be seen in the borazine molecule with polarization of the electron cloud towards the nitrogen atoms. This causes one pair of the lobes to be larger than the other because there are 2 nitrogen atoms on one side and only 1 nitrogen in the other. Benzene typically displays symmetry across its lobes.
|}

File:BORAZ MO20.PNG

2018-05-18T13:08:50Z

Js2016:

File:BENZ MO20.PNG

2018-05-18T13:07:49Z

Js2016:

Y2inorg js2016

2018-05-18T12:56:18Z

Js2016: /* MO comparison */

== Example data set ==
=== BH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000203 0.000450 YES
RMS Force 0.000098 0.000300 YES
Maximum Displacement 0.000867 0.001800 YES
RMS Displacement 0.000415 0.001200 YES

Frequency analysis log file [[Media:JS2016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -0.2263 -0.1037 -0.0054 47.9770 49.0378 49.0383
Low frequencies --- 1163.7209 1213.6704 1213.6731
</pre>

<jmol><jmolApplet>
<title>optimised BH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Optimised BH3 vibrational analysis
! Mode # !! Frequency (cm-1) !! Infrared !! IR active? !! Vibration type
|-
| 1 || 1164 || 92 || Yes || Bond angle deformation
|-
| 2 || 1214 || 14 || Yes || Bond angle deformation
|-
| 3 || 1214 || 14 || Yes || Bond angle deformation
|-
| 4 || 2580 || 0 || No || Bond stretch
|-
| 5 || 2713 || 126 || Yes || Bond stretch
|-
| 6 || 2713 || 126 || Yes || Bond stretch
|}

==== IR spectrum of BH3 ====
[[File:BH3_FREQ_VT_js2016.png]]

Although the vibrational analysis clearly shows 6 modes of vibration, there are fewer peaks shown in the IR spectrum. This is because one mode (#4) has no intensity and there are two different degenerate pairs of vibrations, one set being a bond angle deformation (modes 2 and 3) and the other a bond stretching (modes 5 and 6). Hence there is no signal for mode 4 and one peak shown for modes 2 and 3, and one peak shown for modes 5 and 6. In total, only 3 peaks appear in the IR spectrum.

==== MO diagram of BH3 ====

[[File:BH3_MOdiagram_js2016.png|BH3_MOdiagram_js2016.png]]

The LCAO of MOs show a great deal of similarity with the "real" MOs obtained from Gaussian as seen from the MO diagram.<ref name="1st"/> There are slight differences i.e. with MOs a``2 and a`1. However, one can accurately predict the "real" MOs with good confidence using qualitative MO theory.

=== NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000012 0.001800 YES
RMS Displacement 0.000008 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000122 0.000450 YES
RMS Force 0.000058 0.000300 YES
Maximum Displacement 0.000513 0.001800 YES
RMS Displacement 0.000296 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3BH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3BH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3-NH3 association energies ===

<pre>
E(NH3) = -56.55776873 au
E(BH3) = -26.61532342 au
E(NH3BH3) = -83.22468888 au

ΔE = [E(NH3)+E(BH3)] + E(NH3BH3)
ΔE = 0.05159673 au = 135 kJ/mol
</pre>

The B-N dative bond is weak with a dissociation energy of 135 kJ/mol, significantly lower than the C-I bond (213 kJ/mol) which is another comparatively weak bond.<ref name="2nd" />

=== BBr3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BBR3_OPT_GEN_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000015 0.000450 YES
RMS Force 0.000009 0.000300 YES
Maximum Displacement 0.000058 0.001800 YES
RMS Displacement 0.000042 0.001200 YES

Frequency analysis log file [[Media:JS2016_BBR3_FREQ_GEN.log]]

<pre>
Low frequencies --- -4.3191 -2.7656 -2.2989 -0.0002 -0.0001 0.0002
Low frequencies --- 155.8708 155.9430 267.6975
</pre>

<jmol><jmolApplet>
<title>optimised BBr3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BBR3_FREQ_GEN.log</uploadedFileContents>
</jmolApplet></jmol>

Link: http://hdl.handle.net/10042/202424

{{DOI|10042/202424}}

<references>
<ref name="1st">MO diagram used is from tutorial sheet of Patricia Hunt.</ref>
<ref name="2nd">https://ch301.cm.utexas.edu/section2.php?target=thermo/thermochemistry/enthalpy-bonds.html</ref>
</references>

== Aromaticity ==

=== Benzene ===
'''B3LYP/6-31G(d,p) level'''

[[File:BENZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000198 0.000450 YES
RMS Force 0.000082 0.000300 YES
Maximum Displacement 0.000849 0.001800 YES
RMS Displacement 0.000305 0.001200 YES

Frequency analysis log file [[Media:JS2016_BENZ_FREQ.LOG]]

<pre>
Low frequencies --- -11.6728 -0.0004 0.0007 0.0009 6.6686 15.6846
Low frequencies --- 414.0392 414.6031 621.0860
</pre>

<jmol><jmolApplet>
<title>Optimised Benzene molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BENZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== Borazine ===
'''B3LYP/6-31G(d,p) level'''

[[File:BORAZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000085 0.000450 YES
RMS Force 0.000033 0.000300 YES
Maximum Displacement 0.000249 0.001800 YES
RMS Displacement 0.000077 0.001200 YES

Frequency analysis log file [[Media:JS2016_BORAZ_FREQ.LOG]]

<pre>
Low frequencies --- -17.8308 -12.6833 -9.1489 -0.0008 -0.0006 0.0012
Low frequencies --- 289.0049 289.4700 404.2277
</pre>

<jmol><jmolApplet>
<title>Optimised Borazine molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BORAZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== NBO charge analysis ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! Benzene !! Borazine
|-
| [[File:BENZ_CD.png]] || [[File:BORAZ_CD.png]]
|}

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! !! Benzene !! !! Borazine
|-
| Carbon || -0.24 || Nitrogen || -1.102
|-
| Hydrogen || 0.24 || Boron || 0.747
|-
| || || Hydrogen (N-H) || 0.432
|-
| || || Hydrogen (B-H) || -0.077
|}

The charge distribution diagram of benzene illustrates that most of the electron density is localized on the pi ring system. The point group of benzene is D6h which corresponds to a charge of -0.24 on all the carbon atoms and a charge of 0.24 on all the hydrogen atoms as shown. Borazine, on the other hand, has a rather more complex charge distribution. The nitrogen atoms have the most negative charge (-1.102) so most of the electron density will be found at and very close to these nitrogen atoms. The neighbouring atoms to nitrogen as a result have positive charges, where boron has a charge of 0.747 and hydrogen (B-H) has a charge of 0.432. Lastly, the hydrogen atoms bonded to boron have a charge of -0.077. Albeit a small negative charge, these hydrogen atoms have retained electron density because of their distance from the electronegative nitrogen atoms.

=== MO comparison ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! MO # !! MO in benzene !! MO # !! MO in borazine !! Description
|-
| 8 || [[File:BENZ_MO8.png]] || 8 || [[File:BORAZ_MO8.png]] || This MO has the second lowest in energy bonding MO in both complexes. MO 8 in benzene has significant symmetry with one half of the molecule (3 consecutive C-H units on the ring) in phase and the other out of phase. MO 8 in borazine has less symmetry due to electron density being drawn to the nitrogen atoms, causing very little contribution from some of the hydrogen atoms.
|-
| 13 || [[File:BENZ_MO13.PNG]] || 16 || [[File:BORAZ_MO16.PNG]] || Both of these MOs exhibit anti-bonding character with orbital lobes focused onto one ring atom (C/B/N) and one hydrogen atom. Again the MO in benzene has a high degree of symmetry and the MO in borazine has significant distortions. However, the boron orbitals are higher in energy and therefore must contribute more to these anti-bonding orbitals. This is why larger lobes are present around the boron atoms.
|-
| || [[File:BENZ_MO8.png]] || || [[File:BORAZ_MO8.png]] || 0.432
|}

Y2inorg js2016

2018-05-18T12:45:32Z

Js2016: /* MO comparison */

== Example data set ==
=== BH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000203 0.000450 YES
RMS Force 0.000098 0.000300 YES
Maximum Displacement 0.000867 0.001800 YES
RMS Displacement 0.000415 0.001200 YES

Frequency analysis log file [[Media:JS2016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -0.2263 -0.1037 -0.0054 47.9770 49.0378 49.0383
Low frequencies --- 1163.7209 1213.6704 1213.6731
</pre>

<jmol><jmolApplet>
<title>optimised BH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Optimised BH3 vibrational analysis
! Mode # !! Frequency (cm-1) !! Infrared !! IR active? !! Vibration type
|-
| 1 || 1164 || 92 || Yes || Bond angle deformation
|-
| 2 || 1214 || 14 || Yes || Bond angle deformation
|-
| 3 || 1214 || 14 || Yes || Bond angle deformation
|-
| 4 || 2580 || 0 || No || Bond stretch
|-
| 5 || 2713 || 126 || Yes || Bond stretch
|-
| 6 || 2713 || 126 || Yes || Bond stretch
|}

==== IR spectrum of BH3 ====
[[File:BH3_FREQ_VT_js2016.png]]

Although the vibrational analysis clearly shows 6 modes of vibration, there are fewer peaks shown in the IR spectrum. This is because one mode (#4) has no intensity and there are two different degenerate pairs of vibrations, one set being a bond angle deformation (modes 2 and 3) and the other a bond stretching (modes 5 and 6). Hence there is no signal for mode 4 and one peak shown for modes 2 and 3, and one peak shown for modes 5 and 6. In total, only 3 peaks appear in the IR spectrum.

==== MO diagram of BH3 ====

[[File:BH3_MOdiagram_js2016.png|BH3_MOdiagram_js2016.png]]

The LCAO of MOs show a great deal of similarity with the "real" MOs obtained from Gaussian as seen from the MO diagram.<ref name="1st"/> There are slight differences i.e. with MOs a``2 and a`1. However, one can accurately predict the "real" MOs with good confidence using qualitative MO theory.

=== NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000012 0.001800 YES
RMS Displacement 0.000008 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000122 0.000450 YES
RMS Force 0.000058 0.000300 YES
Maximum Displacement 0.000513 0.001800 YES
RMS Displacement 0.000296 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3BH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3BH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3-NH3 association energies ===

<pre>
E(NH3) = -56.55776873 au
E(BH3) = -26.61532342 au
E(NH3BH3) = -83.22468888 au

ΔE = [E(NH3)+E(BH3)] + E(NH3BH3)
ΔE = 0.05159673 au = 135 kJ/mol
</pre>

The B-N dative bond is weak with a dissociation energy of 135 kJ/mol, significantly lower than the C-I bond (213 kJ/mol) which is another comparatively weak bond.<ref name="2nd" />

=== BBr3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BBR3_OPT_GEN_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000015 0.000450 YES
RMS Force 0.000009 0.000300 YES
Maximum Displacement 0.000058 0.001800 YES
RMS Displacement 0.000042 0.001200 YES

Frequency analysis log file [[Media:JS2016_BBR3_FREQ_GEN.log]]

<pre>
Low frequencies --- -4.3191 -2.7656 -2.2989 -0.0002 -0.0001 0.0002
Low frequencies --- 155.8708 155.9430 267.6975
</pre>

<jmol><jmolApplet>
<title>optimised BBr3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BBR3_FREQ_GEN.log</uploadedFileContents>
</jmolApplet></jmol>

Link: http://hdl.handle.net/10042/202424

{{DOI|10042/202424}}

<references>
<ref name="1st">MO diagram used is from tutorial sheet of Patricia Hunt.</ref>
<ref name="2nd">https://ch301.cm.utexas.edu/section2.php?target=thermo/thermochemistry/enthalpy-bonds.html</ref>
</references>

== Aromaticity ==

=== Benzene ===
'''B3LYP/6-31G(d,p) level'''

[[File:BENZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000198 0.000450 YES
RMS Force 0.000082 0.000300 YES
Maximum Displacement 0.000849 0.001800 YES
RMS Displacement 0.000305 0.001200 YES

Frequency analysis log file [[Media:JS2016_BENZ_FREQ.LOG]]

<pre>
Low frequencies --- -11.6728 -0.0004 0.0007 0.0009 6.6686 15.6846
Low frequencies --- 414.0392 414.6031 621.0860
</pre>

<jmol><jmolApplet>
<title>Optimised Benzene molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BENZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== Borazine ===
'''B3LYP/6-31G(d,p) level'''

[[File:BORAZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000085 0.000450 YES
RMS Force 0.000033 0.000300 YES
Maximum Displacement 0.000249 0.001800 YES
RMS Displacement 0.000077 0.001200 YES

Frequency analysis log file [[Media:JS2016_BORAZ_FREQ.LOG]]

<pre>
Low frequencies --- -17.8308 -12.6833 -9.1489 -0.0008 -0.0006 0.0012
Low frequencies --- 289.0049 289.4700 404.2277
</pre>

<jmol><jmolApplet>
<title>Optimised Borazine molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BORAZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== NBO charge analysis ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! Benzene !! Borazine
|-
| [[File:BENZ_CD.png]] || [[File:BORAZ_CD.png]]
|}

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! !! Benzene !! !! Borazine
|-
| Carbon || -0.24 || Nitrogen || -1.102
|-
| Hydrogen || 0.24 || Boron || 0.747
|-
| || || Hydrogen (N-H) || 0.432
|-
| || || Hydrogen (B-H) || -0.077
|}

The charge distribution diagram of benzene illustrates that most of the electron density is localized on the pi ring system. The point group of benzene is D6h which corresponds to a charge of -0.24 on all the carbon atoms and a charge of 0.24 on all the hydrogen atoms as shown. Borazine, on the other hand, has a rather more complex charge distribution. The nitrogen atoms have the most negative charge (-1.102) so most of the electron density will be found at and very close to these nitrogen atoms. The neighbouring atoms to nitrogen as a result have positive charges, where boron has a charge of 0.747 and hydrogen (B-H) has a charge of 0.432. Lastly, the hydrogen atoms bonded to boron have a charge of -0.077. Albeit a small negative charge, these hydrogen atoms have retained electron density because of their distance from the electronegative nitrogen atoms.

=== MO comparison ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! MO # !! MO in benzene !! MO # !! MO in borazine !! Description
|-
| 8 || [[File:BENZ_MO8.png]] || 8 || [[File:BORAZ_MO8.png]] || This MO has the second lowest in energy bonding MO in both complexes. MO 8 in benzene has significant symmetry with one half of the molecule (3 consecutive C-H units on the ring) in phase and the other out of phase. MO 8 in borazine has less symmetry due to electron density being drawn to the nitrogen atoms, causing very little contribution from some of the hydrogen atoms.
|-
| 13 || [[File:BENZ_MO13.PNG]] || 16 || [[File:BORAZ_MO16.PNG]] ||
|-
| || [[File:BENZ_MO8.png]] || || [[File:BORAZ_MO8.png]] || 0.432
|}

Y2inorg js2016

2018-05-18T12:44:59Z

Js2016: /* MO comparison */

== Example data set ==
=== BH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000203 0.000450 YES
RMS Force 0.000098 0.000300 YES
Maximum Displacement 0.000867 0.001800 YES
RMS Displacement 0.000415 0.001200 YES

Frequency analysis log file [[Media:JS2016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -0.2263 -0.1037 -0.0054 47.9770 49.0378 49.0383
Low frequencies --- 1163.7209 1213.6704 1213.6731
</pre>

<jmol><jmolApplet>
<title>optimised BH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Optimised BH3 vibrational analysis
! Mode # !! Frequency (cm-1) !! Infrared !! IR active? !! Vibration type
|-
| 1 || 1164 || 92 || Yes || Bond angle deformation
|-
| 2 || 1214 || 14 || Yes || Bond angle deformation
|-
| 3 || 1214 || 14 || Yes || Bond angle deformation
|-
| 4 || 2580 || 0 || No || Bond stretch
|-
| 5 || 2713 || 126 || Yes || Bond stretch
|-
| 6 || 2713 || 126 || Yes || Bond stretch
|}

==== IR spectrum of BH3 ====
[[File:BH3_FREQ_VT_js2016.png]]

Although the vibrational analysis clearly shows 6 modes of vibration, there are fewer peaks shown in the IR spectrum. This is because one mode (#4) has no intensity and there are two different degenerate pairs of vibrations, one set being a bond angle deformation (modes 2 and 3) and the other a bond stretching (modes 5 and 6). Hence there is no signal for mode 4 and one peak shown for modes 2 and 3, and one peak shown for modes 5 and 6. In total, only 3 peaks appear in the IR spectrum.

==== MO diagram of BH3 ====

[[File:BH3_MOdiagram_js2016.png|BH3_MOdiagram_js2016.png]]

The LCAO of MOs show a great deal of similarity with the "real" MOs obtained from Gaussian as seen from the MO diagram.<ref name="1st"/> There are slight differences i.e. with MOs a``2 and a`1. However, one can accurately predict the "real" MOs with good confidence using qualitative MO theory.

=== NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000012 0.001800 YES
RMS Displacement 0.000008 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000122 0.000450 YES
RMS Force 0.000058 0.000300 YES
Maximum Displacement 0.000513 0.001800 YES
RMS Displacement 0.000296 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3BH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3BH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3-NH3 association energies ===

<pre>
E(NH3) = -56.55776873 au
E(BH3) = -26.61532342 au
E(NH3BH3) = -83.22468888 au

ΔE = [E(NH3)+E(BH3)] + E(NH3BH3)
ΔE = 0.05159673 au = 135 kJ/mol
</pre>

The B-N dative bond is weak with a dissociation energy of 135 kJ/mol, significantly lower than the C-I bond (213 kJ/mol) which is another comparatively weak bond.<ref name="2nd" />

=== BBr3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BBR3_OPT_GEN_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000015 0.000450 YES
RMS Force 0.000009 0.000300 YES
Maximum Displacement 0.000058 0.001800 YES
RMS Displacement 0.000042 0.001200 YES

Frequency analysis log file [[Media:JS2016_BBR3_FREQ_GEN.log]]

<pre>
Low frequencies --- -4.3191 -2.7656 -2.2989 -0.0002 -0.0001 0.0002
Low frequencies --- 155.8708 155.9430 267.6975
</pre>

<jmol><jmolApplet>
<title>optimised BBr3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BBR3_FREQ_GEN.log</uploadedFileContents>
</jmolApplet></jmol>

Link: http://hdl.handle.net/10042/202424

{{DOI|10042/202424}}

<references>
<ref name="1st">MO diagram used is from tutorial sheet of Patricia Hunt.</ref>
<ref name="2nd">https://ch301.cm.utexas.edu/section2.php?target=thermo/thermochemistry/enthalpy-bonds.html</ref>
</references>

== Aromaticity ==

=== Benzene ===
'''B3LYP/6-31G(d,p) level'''

[[File:BENZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000198 0.000450 YES
RMS Force 0.000082 0.000300 YES
Maximum Displacement 0.000849 0.001800 YES
RMS Displacement 0.000305 0.001200 YES

Frequency analysis log file [[Media:JS2016_BENZ_FREQ.LOG]]

<pre>
Low frequencies --- -11.6728 -0.0004 0.0007 0.0009 6.6686 15.6846
Low frequencies --- 414.0392 414.6031 621.0860
</pre>

<jmol><jmolApplet>
<title>Optimised Benzene molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BENZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== Borazine ===
'''B3LYP/6-31G(d,p) level'''

[[File:BORAZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000085 0.000450 YES
RMS Force 0.000033 0.000300 YES
Maximum Displacement 0.000249 0.001800 YES
RMS Displacement 0.000077 0.001200 YES

Frequency analysis log file [[Media:JS2016_BORAZ_FREQ.LOG]]

<pre>
Low frequencies --- -17.8308 -12.6833 -9.1489 -0.0008 -0.0006 0.0012
Low frequencies --- 289.0049 289.4700 404.2277
</pre>

<jmol><jmolApplet>
<title>Optimised Borazine molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BORAZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== NBO charge analysis ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! Benzene !! Borazine
|-
| [[File:BENZ_CD.png]] || [[File:BORAZ_CD.png]]
|}

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! !! Benzene !! !! Borazine
|-
| Carbon || -0.24 || Nitrogen || -1.102
|-
| Hydrogen || 0.24 || Boron || 0.747
|-
| || || Hydrogen (N-H) || 0.432
|-
| || || Hydrogen (B-H) || -0.077
|}

The charge distribution diagram of benzene illustrates that most of the electron density is localized on the pi ring system. The point group of benzene is D6h which corresponds to a charge of -0.24 on all the carbon atoms and a charge of 0.24 on all the hydrogen atoms as shown. Borazine, on the other hand, has a rather more complex charge distribution. The nitrogen atoms have the most negative charge (-1.102) so most of the electron density will be found at and very close to these nitrogen atoms. The neighbouring atoms to nitrogen as a result have positive charges, where boron has a charge of 0.747 and hydrogen (B-H) has a charge of 0.432. Lastly, the hydrogen atoms bonded to boron have a charge of -0.077. Albeit a small negative charge, these hydrogen atoms have retained electron density because of their distance from the electronegative nitrogen atoms.

=== MO comparison ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! MO # !! MO in benzene !! MO # !! MO in borazine !! Description
|-
| 8 || [[File:BENZ_MO8.png]] || 8 || [[File:BORAZ_MO8.png]] || This MO has the second lowest in energy bonding MO in both complexes. MO 8 in benzene has significant symmetry with one half of the molecule (3 consecutive C-H units on the ring) in phase and the other out of phase. MO 8 in borazine has less symmetry due to electron density being drawn to the nitrogen atoms, causing very little contribution from some of the hydrogen atoms.
|-
| 13 || [[File:BENZ_MO13.png]] || 16 || [[File:BORAZ_MO16.png]] ||
|-
| || [[File:BENZ_MO8.png]] || || [[File:BORAZ_MO8.png]] || 0.432
|}

Y2inorg js2016

2018-05-18T12:44:43Z

Js2016: /* MO comparison */

== Example data set ==
=== BH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000203 0.000450 YES
RMS Force 0.000098 0.000300 YES
Maximum Displacement 0.000867 0.001800 YES
RMS Displacement 0.000415 0.001200 YES

Frequency analysis log file [[Media:JS2016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -0.2263 -0.1037 -0.0054 47.9770 49.0378 49.0383
Low frequencies --- 1163.7209 1213.6704 1213.6731
</pre>

<jmol><jmolApplet>
<title>optimised BH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Optimised BH3 vibrational analysis
! Mode # !! Frequency (cm-1) !! Infrared !! IR active? !! Vibration type
|-
| 1 || 1164 || 92 || Yes || Bond angle deformation
|-
| 2 || 1214 || 14 || Yes || Bond angle deformation
|-
| 3 || 1214 || 14 || Yes || Bond angle deformation
|-
| 4 || 2580 || 0 || No || Bond stretch
|-
| 5 || 2713 || 126 || Yes || Bond stretch
|-
| 6 || 2713 || 126 || Yes || Bond stretch
|}

==== IR spectrum of BH3 ====
[[File:BH3_FREQ_VT_js2016.png]]

Although the vibrational analysis clearly shows 6 modes of vibration, there are fewer peaks shown in the IR spectrum. This is because one mode (#4) has no intensity and there are two different degenerate pairs of vibrations, one set being a bond angle deformation (modes 2 and 3) and the other a bond stretching (modes 5 and 6). Hence there is no signal for mode 4 and one peak shown for modes 2 and 3, and one peak shown for modes 5 and 6. In total, only 3 peaks appear in the IR spectrum.

==== MO diagram of BH3 ====

[[File:BH3_MOdiagram_js2016.png|BH3_MOdiagram_js2016.png]]

The LCAO of MOs show a great deal of similarity with the "real" MOs obtained from Gaussian as seen from the MO diagram.<ref name="1st"/> There are slight differences i.e. with MOs a``2 and a`1. However, one can accurately predict the "real" MOs with good confidence using qualitative MO theory.

=== NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000012 0.001800 YES
RMS Displacement 0.000008 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3NH3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:NH3BH3_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000122 0.000450 YES
RMS Force 0.000058 0.000300 YES
Maximum Displacement 0.000513 0.001800 YES
RMS Displacement 0.000296 0.001200 YES

Frequency analysis log file [[Media:JS2016_NH3BH3_FREQ_631G_DP.LOG]]

<pre>
Low frequencies --- -0.0138 -0.0032 -0.0015 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>optimised NH3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_NH3BH3_FREQ_631G_DP.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== BH3-NH3 association energies ===

<pre>
E(NH3) = -56.55776873 au
E(BH3) = -26.61532342 au
E(NH3BH3) = -83.22468888 au

ΔE = [E(NH3)+E(BH3)] + E(NH3BH3)
ΔE = 0.05159673 au = 135 kJ/mol
</pre>

The B-N dative bond is weak with a dissociation energy of 135 kJ/mol, significantly lower than the C-I bond (213 kJ/mol) which is another comparatively weak bond.<ref name="2nd" />

=== BBr3 molecule ===

'''B3LYP/6-31G(d,p) level'''

[[File:BBR3_OPT_GEN_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000015 0.000450 YES
RMS Force 0.000009 0.000300 YES
Maximum Displacement 0.000058 0.001800 YES
RMS Displacement 0.000042 0.001200 YES

Frequency analysis log file [[Media:JS2016_BBR3_FREQ_GEN.log]]

<pre>
Low frequencies --- -4.3191 -2.7656 -2.2989 -0.0002 -0.0001 0.0002
Low frequencies --- 155.8708 155.9430 267.6975
</pre>

<jmol><jmolApplet>
<title>optimised BBr3 molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BBR3_FREQ_GEN.log</uploadedFileContents>
</jmolApplet></jmol>

Link: http://hdl.handle.net/10042/202424

{{DOI|10042/202424}}

<references>
<ref name="1st">MO diagram used is from tutorial sheet of Patricia Hunt.</ref>
<ref name="2nd">https://ch301.cm.utexas.edu/section2.php?target=thermo/thermochemistry/enthalpy-bonds.html</ref>
</references>

== Aromaticity ==

=== Benzene ===
'''B3LYP/6-31G(d,p) level'''

[[File:BENZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000198 0.000450 YES
RMS Force 0.000082 0.000300 YES
Maximum Displacement 0.000849 0.001800 YES
RMS Displacement 0.000305 0.001200 YES

Frequency analysis log file [[Media:JS2016_BENZ_FREQ.LOG]]

<pre>
Low frequencies --- -11.6728 -0.0004 0.0007 0.0009 6.6686 15.6846
Low frequencies --- 414.0392 414.6031 621.0860
</pre>

<jmol><jmolApplet>
<title>Optimised Benzene molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BENZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== Borazine ===
'''B3LYP/6-31G(d,p) level'''

[[File:BORAZ_OPT_ST_js2016.png]]

Item Value Threshold Converged?
Maximum Force 0.000085 0.000450 YES
RMS Force 0.000033 0.000300 YES
Maximum Displacement 0.000249 0.001800 YES
RMS Displacement 0.000077 0.001200 YES

Frequency analysis log file [[Media:JS2016_BORAZ_FREQ.LOG]]

<pre>
Low frequencies --- -17.8308 -12.6833 -9.1489 -0.0008 -0.0006 0.0012
Low frequencies --- 289.0049 289.4700 404.2277
</pre>

<jmol><jmolApplet>
<title>Optimised Borazine molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>JS2016_BORAZ_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

=== NBO charge analysis ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! Benzene !! Borazine
|-
| [[File:BENZ_CD.png]] || [[File:BORAZ_CD.png]]
|}

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! !! Benzene !! !! Borazine
|-
| Carbon || -0.24 || Nitrogen || -1.102
|-
| Hydrogen || 0.24 || Boron || 0.747
|-
| || || Hydrogen (N-H) || 0.432
|-
| || || Hydrogen (B-H) || -0.077
|}

The charge distribution diagram of benzene illustrates that most of the electron density is localized on the pi ring system. The point group of benzene is D6h which corresponds to a charge of -0.24 on all the carbon atoms and a charge of 0.24 on all the hydrogen atoms as shown. Borazine, on the other hand, has a rather more complex charge distribution. The nitrogen atoms have the most negative charge (-1.102) so most of the electron density will be found at and very close to these nitrogen atoms. The neighbouring atoms to nitrogen as a result have positive charges, where boron has a charge of 0.747 and hydrogen (B-H) has a charge of 0.432. Lastly, the hydrogen atoms bonded to boron have a charge of -0.077. Albeit a small negative charge, these hydrogen atoms have retained electron density because of their distance from the electronegative nitrogen atoms.

=== MO comparison ===

{| class="wikitable" border="1"
|+ NBO charge distribution diagrams
! MO # !! MO in benzene !! MO # !! MO in borazine !! Description
|-
| 8 || [[File:BENZ_MO8.png]] || 8 || [[File:BORAZ_MO8.png]] || This MO has the second lowest in energy bonding MO in both complexes. MO 8 in benzene has significant symmetry with one half of the molecule (3 consecutive C-H units on the ring) in phase and the other out of phase. MO 8 in borazine has less symmetry due to electron density being drawn to the nitrogen atoms, causing very little contribution from some of the hydrogen atoms.
|-
| 13 || [[File:BENZ_MO8.png]] || 16 || [[File:BORAZ_MO8.png]] ||
|-
| || [[File:BENZ_MO8.png]] || || [[File:BORAZ_MO8.png]] || 0.432
|}

File:BORAZ MO16.PNG

2018-05-18T12:39:29Z

Js2016:

File:BENZ MO13.PNG

2018-05-18T12:39:16Z

Js2016:

Y2inorg js2016