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Re^6: Lack of force constants for bending vibrations in the output file

Vyacheslav
kreme_vg@chemy.kolasc.net.ru


Dear Alex,

thanks for explanation.  I made a series of test calculations in different bases and really, the stretching frequencies are much less sensitive to the choice of internal coordinates compared to the frequencies of angular deformations. This is much better than if it would be otherwise  :-).
When comparing the similar structures the stretching force constants are quite enough for qualitative characteristic of the bond strength.
Thank you very much once more.
     Vyacheslav
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On Sun Sep 30 '12 8:00pm, Alex Granovsky wrote
----------------------------------------------
>Dear Vyacheslav,

>to the best of my understanding, any really "intrinsic" quantity
>like frequency or force constant should not depend on the particular
>way how it is computed. The frequencies and force constants defined
>in the paper by Boatz and Gordon are not "intrinsic" in this sense
>as they are the functions of the particular set of internals used
>to compute them (and this is discussed in some details in the paper
>above). It is mentioned that variations in the values obtained for
>bond stretches are less sensitive to the choice of internals. Thus
>my guess is the rest is too sensitive to worth printing.

>Kind regards,
>Alex
>
>
>


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