Vibrational analysis w/ constraints



Hi,
 	I am interested in doing a vibrational analysis of a Hessian matrix
 calculated for a system that was optimized with geometric constraints.  Can
 anyone point me to literature of this subject?
 	Thanks, Jan Jensen
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 Jan H. Jensen				Assistant Professor
 Department of Chemistry			jan-jensen $#at#$ uiowa.edu
 University of Iowa			Phone:(319) 335-1108
 Iowa City, IA 52242			FAX:  (319) 335-1270
 http://www.uiowa.edu/~chemdept/faculty/jensen/
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