vibrational frequencies and potential energy surface



 Dear all,
 
I am looking for bibliographic references dealing with vibrational frequencies and potential energy surface. Could the frequencies be calculated for each point of the surface or only at a minimum?
 Any reply would be greatly appreciated.
 Thanks in advance.
 CB
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    Dr. BIOT Christophe
    Ingénierie Moléculaire et Biomoléculaire, CP 165/64
    Université Libre de Bruxelles
    50 Av. F.D. Roosevelt
    1050 Bruxelles, BELGIQUE
 Phone: 32-2-650 3001
 Fax:   32-2-650 3606
 E-mail:cbiot ^at^ ulb.ac.be
 http://babylone.ulb.ac.be/~christophe/
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