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On 11/15/2012 10:46 PM, wrote:
<blockquote
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<div style="direction: ltr;font-family: Tahoma;color:
#000000;font-size: 10pt;">Dr. Pounds,
<div>I was successful in getting the rigid scan to work for
hydrogen peroxide. I scanned 200 points from .5 to 10
Angstroms and got the values out of the log file. I fit
the Morse potential to this data and got values of De, a, and
Re. </div>
<div><br>
</div>
<div>I thought that the energy needed to photolize the peroxide
would be the spectroscopic dissociation energy, Do, not De. I
was planning to use equation 13.80 and 13.83 to calculate Do
but I ran into a problem, equation 13.83 requires a reduced
mass which i did not know how to compute for hydrogen
peroxide.</div>
<div><br>
</div>
<div>Next I tried using De as the value and it produced a very
large energy (around 5.1 ev). </div>
<div><br>
</div>
<div>I'm not sure what I should do from here.</div>
<div><br>
</div>
<div><br>
</div>
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<br>
To photolytically dissociate the molecule along the O-O bond you
will have to excite it to some electronic state (represented by a
dissociative potential surface higher in energy than the one you are
calculating). However, you can approximate the minimum amount of
energy that you need to dissociate the molecule by simply
determining the depth of the energy well (or De). <br>
<br>
If we actually calculated the potential surface of the
electronically excited state which was represented by the
dissociative potential, we would have to do A LOT more work. We
would have to explicitly fix the electronic populations and spin
states in each excited state we were following and then compute
potential surfaces to find the one that leads to dissociation along
the O-O bond. Not something I think you guys are up for at this
time.<br>
<br>
On a side note -- when you do a ZINDO calculation it does some of
this "population setting" to predict the vertical excitation
energies to low lying electronic states. <br>
<br>
<pre class="moz-signature" cols="72">--
Andrew J. Pounds, Ph.D. (<a class="moz-txt-link-abbreviated" href="mailto:pounds@theochem.mercer.edu">pounds@theochem.mercer.edu</a>)
Associate Professor of Chemistry and Computer Science
Mercer University, Macon, GA 31207 (478) 301-5627
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