TURBOMOLE Users Forum

TURBOMOLE Modules => Define => Topic started by: monika on January 22, 2007, 09:45:42 AM

Title: optimisation from hessian
Post by: monika on January 22, 2007, 09:45:42 AM

Hello
I would like ask you how can I start optimisation (ri-mp2) from hessian optimized DFT. Which method will be the bast.
 My strukture  has 30 atmos, 440 basis functions, it's open shell. Please for answer.

best regards

Title: Re: optimisation from hessian
Post by: turbomaster on January 23, 2007, 12:36:54 PM

Hello

It is possible to use a calculated Hessian matrix for structure optimizations.

1. When using Jobex/Relax combination you have to modify the $forceinit section
of the "control" file to
$forceinit
   carthess
Additionally, if you use internal coordinates you have to activate the conversion
of force constants matrix from Cartesian to internals by specifying
$interconversion on
   cartesian --> internal  hessian
in the "control" file.
The details are also described in the TM manual under
"Calculation of Molecular Structure and Ab Initio Molecular Dynamics"

2. In the Jobex/Statpt combination the calculated Hessian matrix will
automatically be used if any of the sections $hessian, $hessian (projected),
or $nprhessian is present in the "control" file.