Author Topic: Using define without changing angles  (Read 1720 times)

AndrijaG

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Using define without changing angles
« on: September 21, 2016, 07:10:21 pm »
Hey community,

for my bachelor thesis I was trying to calculate energies (SCF and MP2) from different molecules after changing one bending angle. The problem is that after running my define script for my molecule the other angles were also changed. This causes unintentional energies and I think that the problem come about when I use the ired command to get redundant internals. Is there a way to get redundant internals without changing the angles or a way to freeze the angles before using the ired command.

Thank you!
AndrijaG

This is my define_script:
Code: [Select]
   
   a coord
   idef
   f bend 2 3 1
   
   
   iman
   %s  #changing the angle to the required value
   

   ired

   *
   b all def2-TZVPP
   *
   eht
   y
   0
   y
   scf
   conv
   8
   iter
   300
   
   prop
   esp
   y
   *
   mp2
   freeze
   *
   cbas
   b all def2-TZVPP
   *
   denconv
   0.1E-07
   *
   *

christof.haettig

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Re: Using define without changing angles
« Reply #1 on: October 06, 2016, 05:51:18 pm »
The answer is no.

The redundant internal coordinates allow by construction that the 'frozen' coordinates may still contribute to the 'active' coordinates.

The TmoleX is often a more convenient tool to prepare scans along angles.

Christof