Subject: Ab-initio Force Constants

From: [email-masked] (Dominique Cavagnat)
Date: Fri, 30 Jun 1995 14:16:14 +0200

Hi,

Ab-initio frequency calculations give
force constants in cartesian and internal
coordinates, the units being respectively
hartree/bohr (and not hartree/bohr**2) and
atomic units. Does somebody know how to 
convert them in mdyn/angstrom?

Thanks for your response
 
I will precise this question posted yesterday:

we know the conversion factors for each type
of internal coordinate involved in force constants
(bond-bond, bond-angle and angle-angle). But the
ab-initio force constant values seem not to be
directly transferable with these conversion
factors to do Schachtschneider calculations and
find back ab-initio frequencies. Does somebody
know why?

C. Lapouge

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please send it again, we had problems
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_______________________________|
Christine Lapouge              | 
                               |
Laboratoire de Spectroscopie   |
Moleculaire et Cristalline     |
                               |
Talence                        |
France                         |
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