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From: "Yubo Fan" <yubofan [a] mail.chem.tamu.edu>
Subject: Free energy barrier
To: chemistry [a] ccl.net
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CCLers,

We are trying to calculate the free energy barriers for 
some dissociative reactions. As a model, we scan the B-N 
bondlength in H3B-NH3from the equilibrium distance to 
three times of that, then the frequency analyses were 
performed for each optimized points. Surprisingly, the 
free energies oscilate when the distance is longer than 
about twice of the equilibrium distance. So, we cannot 
find the free energy barrier by this way.

Is there any other way to calculate activation free energy 
for dissociative processes? Or some program available for 
this goal?

Thanks in advance,

Yubo Fan

Chemistry Department at TAMU