CCL:G: Hessian Matrix Generation from Gaussian run to use in ORCA

 Sent to CCL by: Frank Neese [frank.neese,,mpi-mail.mpg.de]
 Dear Pezhman,
 if you look at the format of the .hess file (a simple ASCII file) in ORCA (from
 a simple run), i believe that it is easy to figure out what is what. You have to
 simply write a small script to convert the information from any program into
 ORCA format. Since we are banned by Gaussian we can not provide any help with
 that process. Analytic frequencies in ORCA are forthcoming.
 Good luck and best regards,
 Frank Neese
 Am 21.11.2011 um 14:50 schrieb Pezhman Zarabadi-Poor pzarabadip _ gmail.com:
 >
 > Sent to CCL by: "Pezhman  Zarabadi-Poor" [pzarabadip^^^gmail.com]
 > Dear CCL users,
 >
 > Recently, I faced a problem which your useful notes will be really helpful
 to save my time :)
 >
 > I have optimization and frequency calculation on several organic molecules.
 These calculations have been done using Gaussian 09w. Now, I am trying to use
 ORCA to simulate absorption/fluorescence spectra of those molecules. I need the
 Hessian matrix of my molecules to speedup the calculations. If I want to do the
 whole job again with ORCA, it will take a lot of time to do these calculations.
 Therefore, I became interested to use the available results. I used opt=calcfc
 keyword in Gaussian to obtain force constant matrices in cartesian and internal
 coordinates. My problem is the difference between aforementioned matrices in
 Gaussian and ORCA.
 >
 > Did anyone face similar issue? Your promising emails and answers are really
 appreciated.
 >
 > Kind regards,
 > Pezhman