[molpro-user] Does QSDPATH calculate mass-weighted IRC's ?

harding harding at anl.gov
Thu Feb 8 16:11:53 GMT 2007

  Does anyone know if one can calculate a true IRC (i.e. steepest 
descent in mass-weighted coordinates) using MOLPRO?

   I have been assuming that the OPTG option, QSDPATH, will do this but 
now I am not sure.

   The evidence I have is the following:

 (1) The path that comes from QSDPATH agrees perfectly with the non 
mass-weighted IRC from GAUSSIAN,
        which, of coure, is different from GAUSSIAN's mass-weighted IRC.

 (2) Changing the masses of some of the atoms seems to have no affect on 
the results from a QSDPATH calculation.

   I have also tried the following COORD options:


   Niether of these have any effect on the result.

   Am I missing some option or does MOLPRO not do mass-weighted IRC's ?

   Larry Harding

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