Hi Sindrila,
Brian answered your question.
But have you considered what the umbrella sampling with that reaction
coordinate would do? When going from keto to enol, it tries to
abstract a proton from the alpha-carbon and put it on the oxygen
(which is what you want), ALONG a straight line between the
alpha-carbon and the oxygen (which is probably what you DON'T want).
You're bound to get some very strange geometries and very high
energies, IF you manage to run all windows without further problems
with your QM convergence or structure of your QM region.
A reaction coordinate is really supposed to follow a reasonable
reaction path, which in this case would involve some acid/base outside
your molecule (e.g. water in the case of aqueous solution) and two
proton transfers.
Marc
> On Fri, Jun 21, 2013 at 3:46 AM, Sindrila Dutta banik <
> sindrila.duttabanik.yahoo.com> wrote:
>
>> Dear All,
>>
>> I want to do umbrella sampling for a keto enol tautomerism reaction. I
>> want to define the reaction coordinate as the difference of two bond length
>> (r1-r2). I could not understand how to define it. Please let me know.
>>
>> With regards
>> Sindrila Dutta Banik
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>
>
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Received on Fri Jun 21 2013 - 09:00:03 PDT
