Subject: help with G92 dipole moments

From: Mike McAllister <[email-masked]>
Date: Sat, 28 May 1994 17:08:41 -0400

Hello everyone, I have a rather simple question, and i hope the
answer(s) are equally simple!

#1.  Concerning G92 outputs, i understand that the 'Dipole Moments' 
     that are listed at the end of a run are refering to the 'Standard
     Orientation'. That is, the total dipole moment is independent of
     the orientation, but the components (i.e. X, Y, Z) are necessarily
     dependent on the orientation, correct?? Furthermore, since the 
     standard orientation employed by gaussian is arbitrary, as far as
     i know, then the components of the dipole moment are equally
     arbitrary are they not??? Obviously the choice of orientation does
     not affect the total dipole, thus this is not an arbitrary value.
     So, basically the question is, if one has a series of similar
     compounds and wished to study the dipole moment in terms of the 
     components along X, Y , and Z, how does one ensure that the same
     standard orientation is used for ALL compounds?? I have already
     tried this and what happens is that even though all the Z-matrices
     have the same orientations, the standard orientations come out 
     randomly skewed, that is sometimes the molecules are placed in the
     X-Y plane, sometimes in the X-Z, sometimes in the Y-Z, sometimes
     oriented along Z, sometimes, Y , etc...... This makes analysis of
     the component dipoles meaningless. Is there a way to force G92
     to calculate dipoles components based on the Z-matrix orientations
     instead of the standard orientation??

#2.  In the compressed summary (archive) that is printed for each G92 
     job it lists the 'Dipole' values, in three components, presumably
     X, Y, and Z. What do these values represent, what is their
     relationship to the dipole moment? Are these values dependent on
     the choice of standard orientation as well??

I hope this request makes at least some sense.  
I would appreciate any suggestions from the many Gaussian experts out
there.
Thank you, 
Mike McAllister, U. of Toronto.