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Panwang Zhou
pwzhou@gmail.com

I have tried to request the C2v symmetry in DATA deck and set NOSYM=0 in the control section, however, it seems that this did not take effect, because from the second step, the geometry has changed the symmetry.

On Mon Dec 4 '17 4:47pm, Pedro Silva wrote
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>>Dear Panwang Zhou,

>Your output states that you did not request C2v symmetry in the optimization algorithm. In your DATA deck, you should replace the C1 line by "Cnv  2" , followed by a blank line and by your geometry, suitably rotated/translated/etc to comply with the internal master frame detection conventions:

>By default, the 'master frame' assumes that
>1. z is the principal rotation axis (if any),
>2. x is a perpendicular two-fold axis (if any),
>3. xz is the sigma-v plane (if any), and
>4. xy is the sigma-h plane (if any).
>Use the lowest number rule that applies to your molecule.
>
>
>Some programs (eg. ChemCraft) allow you to select the symmetry and automatically generated properly-formatted $DATA groups to ensure that your computation does not face trouble because of deficient adherence to those conventions.

>