Rep:Mod:Ssn3617

2019-05-16T19:07:28Z

Ssn3617:

== BH3 ==

=== Method and Basis Set ===
* Method: B3LYP
* Basis Set: 6-31G(d,p)

===Summary table of final optimized molecule===
[[File:Ssn_bh3_opt_summ.png]]

=== "Item" table from optimisation ===
<pre>
Item Value Threshold Converged?
Maximum Force 0.000011 0.000450 YES
RMS Force 0.000007 0.000300 YES
Maximum Displacement 0.000042 0.001800 YES
RMS Displacement 0.000027 0.001200 YES
</pre>

===Link to frequency .log file===
[[File:SSN_BH3_FREQ.LOG]]

===Low Frequency lines from .log file===
<pre> Low frequencies --- -7.5936 -1.5614 -0.0054 0.6514 6.9319 7.1055
Low frequencies --- 1162.9677 1213.1634 1213.1661
</pre>

===Jmol image from frequency file===
<jmol><jmolApplet>
<title>Optimized molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>SSN_BH3_FREQ.LOG</uploadedFileContents>
<script>frame 1.2</script>
</jmolApplet></jmol>

===Table of Vibrations===

{| class="wikitable" border="1"
! Mode !! Frequency/ cm-1 !! Intensity !! Symmetry !! IR active/ inactive !! Vibration Type
|-
| 1 || 1164 || 93 || A2" || Active || Bending
|-
| 2 || 1213 || 14 || E' || Active || Bending
|-
| 3 || 1213 || 14 || E' || Active || Bending
|-
| 4 || 2582 || 0 || A1' || Inactive || Stretching
|-
| 5 || 2716 || 126 || E' || Active || Stretching
|-
| 6 || 2716 || 126 || E' || Active || Stretching
|}

===IR Spectrum===
[[File:Ssn_bh3_irspec.png]]

'''Why are there less than six peaks in the spectrum despite there being 6 vibrational modes?'''

There are 2 sets of degenerate modes: mode 2 and 3 (bending), and mode 5 and 6 (stretching).
On top of that, mode 4 is IR inactive as it does not result in a net change in dipole moment due to the simultaneous stretching of the 3 B-H bonds to the same extent.
Taking the above into consideration, 3 peaks are expected, and that is observed in the IR spectrum obtained using GaussView.

===MO diagram of BH3===

'''Are there any significant differences between the real and LCAO MOs?'''
'''What does this say about the accuracy and usefulness of qualitative MO theory?'''

== NH3 ==

=== Method and Basis Set ===
* Method: B3LYP
* Basis Set: 6-31G(d,p)

===Summary table of final optimized molecule===
[[File:Ssn_nh3_opt_summ2.png]]

=== "Item" table from optimisation ===
<pre>
Item Value Threshold Converged?
Maximum Force 0.000006 0.000015 YES
RMS Force 0.000004 0.000010 YES
Maximum Displacement 0.000016 0.000060 YES
RMS Displacement 0.000011 0.000040 YES
</pre>

===Link to frequency .log file===
[[File:SSN_NH3_OPT_FREQ2.LOG]]

===Low Frequency lines from .log file===
<pre>
Low frequencies --- -0.0130 -0.0016 -0.0007 7.0749 8.0912 8.0915
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

===Jmol image from frequency file===
<jmol><jmolApplet>
<title>Optimized molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>SSN_NH3_OPT_FREQ2.LOG</uploadedFileContents>
<script>frame 1.6</script>
</jmolApplet></jmol>

== NH3BH3 ==

=== Method and Basis Set ===
* Method: B3LYP
* Basis Set: 6-31G(d,p)

===Summary table of final optimized molecule===
[[File:Ssn_nh3bh3_opt_summ.png]]

=== "Item" table from optimisation ===
<pre>
Item Value Threshold Converged?
Maximum Force 0.000233 0.000450 YES
RMS Force 0.000083 0.000300 YES
Maximum Displacement 0.000820 0.001800 YES
RMS Displacement 0.000318 0.001200 YES
</pre>

===Link to frequency .log file===
[[File:SSN_NH3BH3_FREQ.LOG]]

===Low Frequency lines from .log file===
<pre>
Low frequencies --- -0.0276 -0.0070 -0.0053 10.1011 10.1486 37.9344
Low frequencies --- 265.3079 634.4241 639.2084
</pre>

===Jmol image from frequency file===
<jmol><jmolApplet>
<title>Optimized molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>SSN_NH3BH3_FREQ.LOG</uploadedFileContents>
<script>frame 1.2</script>
</jmolApplet></jmol>

==Association Energy==
===Calculation of Association Energy===
Values obtained using the same method and basis set.
* E(NH3) = -56.55777 AU
* E(BH3) = -26.61532 AU
* E(NH3BH3) = -83.22469 AU

ΔE = E(NH3BH3) - [E(NH3) + E(BH3)] = −0.05160 AU = (−0.05160 x 2625.50) kJ/ mol-1 = −135.47580 kJ/ mol-1

===Bond strength of NH3BH3===
Based on the energy calculation carried out above, we can take bond energy of the B-N bond to be equal in magnitude to that of the association energy, such that bond energy of dative B-N bond = 135.47580 kJ/ mol-1. Comparing to the known average bond energy of a C-C bond = 346 kJ/ mol-1, as well as average bond energy of I-I bond = 150 kJ/ mol-1, it can be concluded that the dative B-N bond is weak. Dative B-N has a lower bond energy than expected, especially with comparison to I-I. It is expected that B-N, since involving smaller atoms and hence having a smaller bond length, will have a stronger bond than I-I which has larger atoms that lead to a larger bond length.

== NI3 ==

=== Method and Basis Set ===
* Method: B3LYP
* Basis Set: 6-31G(d,p) LANL2DZ

===Summary table of final optimized molecule===
[[File:Ssn_ni3_opt_summ.png]]

=== "Item" table from optimisation ===
<pre>
Item Value Threshold Converged?
Maximum Force 0.000140 0.000450 YES
RMS Force 0.000092 0.000300 YES
Maximum Displacement 0.001123 0.001800 YES
RMS Displacement 0.000804 0.001200 YES
</pre>

===Link to frequency .log file===
[[File:SSN_NI3_FREQ.LOG]]

===Low Frequency lines from .log file===
<pre>
Low frequencies --- -12.7232 -12.7172 -6.4215 -0.0039 0.0189 0.0620
Low frequencies --- 101.0767 101.0775 147.4581
</pre>

===Jmol image from frequency file===
<jmol><jmolApplet>
<title>Optimized molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>SSN_NI3_FREQ.LOG</uploadedFileContents>
<script>frame 1.2</script>
</jmolApplet></jmol>

===Optimized N-I distance===
2.184 Å [Bond distances are accurate to ≈ 0.001 Å]

Ssn3617: /* BH3 */

Rep:Mod:Ssn3617

2019-05-16T13:42:32Z

Ssn3617: /* BH3 */

== BH3 ==

=== Method and Basis Set ===
* Method: B3LYP
* Basis Set: 6-31G(d,p)
[[File:Ssn_bh3_opt_summ.png|thumb|Summary table of final optimized molecule]]

=== "Item" table from optimisation ===
<pre> Item Value Threshold Converged?

Maximum Force 0.000012 0.000450 YES

RMS Force 0.000008 0.000300 YES

Maximum Displacement 0.000064 0.001800 YES

RMS Displacement 0.000039 0.001200 YES

</pre>

===Link to frequency .log file===
[[File:SSN_BH3_FREQ.LOG]]

===Low Frequency lines from .log file===
<pre> Low frequencies --- -7.5936 -1.5614 -0.0054 0.6514 6.9319 7.1055
Low frequencies --- 1162.9677 1213.1634 1213.1661
</pre>

===Jmol image from frequency file===
<jmol><jmolApplet>
<title>Optimized molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>SSN_BH3_FREQ.LOG</uploadedFileContents>
<script>frame 1.8</script>
</jmolApplet></jmol>

===Table of Vibrations===

{| class="wikitable" border="1"
! Mode !! Frequency/ cm-1 !! Intensity !! Symmetry !! IR active/ inactive !! Vibration Type
|-
| 1 || 1164 || 93 || A2" || Active || Bending
|-
| 2 || 1213 || 14 || E' || Active || Bending
|-
| 3 || 1213 || 14 || E' || Active || Bending
|-
| 4 || 2582 || 0 || A1' || Inactive || Stretching
|-
| 5 || 2716 || 126 || E' || Active || Stretching
|-
| 6 || 2716 || 126 || E' || Active || Stretching
|}

===IR Spectrum===
[[File:Ssn_bh3_irspec.png]]

'''Why are there less than six peaks in the spectrum despite there being 6 vibrational modes?'''

There are 2 sets of degenerate modes: mode 2 and 3 (bending), and mode 5 and 6 (stretching).
On top of that, mode 4 is IR inactive as it does not result in a net change in dipole moment due to the simultaneous stretching of the 3 B-H bonds to the same extent.
Taking the above into consideration, 3 peaks are expected, and that is observed in the IR spectrum obtained using GaussView.

File:Ssn bh3 opt summ.png

2019-05-16T13:39:59Z

Ssn3617:

Rep:Mod:Ssn3617

2019-05-16T13:34:40Z

Ssn3617:

== BH3 ==

=== Method and Basis Set ===
* Method: B3LYP
* Basis Set: 6-31G(d,p)

===add an image of the summary table produced by gaussview===

=== "Item" table from optimisation ===
<pre> Item Value Threshold Converged?

Maximum Force 0.000012 0.000450 YES

RMS Force 0.000008 0.000300 YES

Maximum Displacement 0.000064 0.001800 YES

RMS Displacement 0.000039 0.001200 YES

</pre>

===Link to frequency .log file===
[[File:SSN_BH3_FREQ.LOG]]

===Low Frequency lines from .log file===
<pre> Low frequencies --- -7.5936 -1.5614 -0.0054 0.6514 6.9319 7.1055
Low frequencies --- 1162.9677 1213.1634 1213.1661
</pre>

===Jmol image from frequency file===
<jmol><jmolApplet>
<title>Optimized molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>SSN_BH3_FREQ.LOG</uploadedFileContents>
<script>frame 1.8</script>
</jmolApplet></jmol>

===Table of Vibrations===

{| class="wikitable" border="1"
! Mode !! Frequency/ cm-1 !! Intensity !! Symmetry !! IR active/ inactive !! Vibration Type
|-
| 1 || 1164 || 93 || A2" || Active || Bending
|-
| 2 || 1213 || 14 || E' || Active || Bending
|-
| 3 || 1213 || 14 || E' || Active || Bending
|-
| 4 || 2582 || 0 || A1' || Inactive || Stretching
|-
| 5 || 2716 || 126 || E' || Active || Stretching
|-
| 6 || 2716 || 126 || E' || Active || Stretching
|}

===IR Spectrum===
[[File:Ssn_bh3_irspec.png]]

'''Why are there less than six peaks in the spectrum despite there being 6 vibrational modes?'''

There are 2 sets of degenerate modes: mode 2 and 3 (bending), and mode 5 and 6 (stretching).
On top of that, mode 4 is IR inactive as it does not result in a net change in dipole moment due to the simultaneous stretching of the 3 B-H bonds to the same extent.
Taking the above into consideration, 3 peaks are expected, and that is observed in the IR spectrum obtained using GaussView.

Rep:Mod:Ssn3617

2019-05-16T13:32:17Z

Ssn3617:

File:Ssn bh3 irspec.png

2019-05-16T13:26:09Z

Ssn3617:

Rep:Mod:Ssn3617

2019-05-16T13:17:26Z

Ssn3617:

== BH3 ==

=== Method and Basis Set ===
* Method: B3LYP
* Basis Set: 6-31G(d,p)

===add an image of the summary table produced by gaussview===

=== "Item" table from optimisation ===
<pre> Item Value Threshold Converged?

Maximum Force 0.000012 0.000450 YES

RMS Force 0.000008 0.000300 YES

Maximum Displacement 0.000064 0.001800 YES

RMS Displacement 0.000039 0.001200 YES

</pre>

===Link to frequency .log file===
[[File:SSN_BH3_FREQ.LOG]]

===Low Frequency lines from .log file===
<pre> Low frequencies --- -7.5936 -1.5614 -0.0054 0.6514 6.9319 7.1055
Low frequencies --- 1162.9677 1213.1634 1213.1661
</pre>

===Jmol image from frequency file===
<jmol><jmolApplet>
<title>Optimized molecule</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>SSN_BH3_FREQ.LOG</uploadedFileContents>
<script>frame 1.8</script>
</jmolApplet></jmol>

===Table of Vibrations===

{| class="wikitable" border="1"
! Mode !! Frequency/ cm-1 !! Intensity !! Symmetry
|-
| 1 || 1164 || 93 || A2"
|-
| 2 || 1213 || 14 || E'
|-
| 3 || 1213 || 14 || E'
|-
| 4 || 2582 || 0 || A1'
|-
| 5 || 2716 || 126 || E'
|-
| 6 || 2716 || 126 || E'
|}

Include a table listing the vibrations,their intensity and symmetry in your wiki. Careful with the accuracy of your numbers, check the accuracy page! Indicate in your table if a vibration is IR active or not and describe what kind of vibration it is.
Take a snap-shot of the spectrum and include it in your wiki.
In your wiki explain why are there less than six peaks in the spectrum, when there are obviously six vibrations.

Rep:Mod:Ssn3617

2019-05-16T12:52:48Z

Ssn3617:

Rep:Mod:Ssn3617

2019-05-16T12:50:17Z

Ssn3617: