[molpro-user] To understand the reason for difference betweeen two outputs for the same situation developed by MOLPRO

[Peter Knowles]

Dear Professor Chandra,

As I mentioned twice before to you:

Once again, the geometries are not different, in the sense that the hamiltonian is really the same in the two cases. They are at different cartesian coordinates, but this just means that the origin and orientation of the cartesian frame is different.  As I wrote to you earlier, it is easily possible that you get these differences, depending on whether you supplied cartesian or internal coordinates, on whether you used NOORIENT, and maybe on geometry optimiser options.

Best regards,
Peter Knowles 

> On 10 Nov 2017, at 06:50, Prof. Suresh Chandra <suresh492000 at yahoo.co.in> wrote:
> 
> Dear Friends,
> 
> We have optimized H2CS on 21 September 2017 and on 1 April 2014 with the help of
> MOLPRO using the same basis-set and the same method, but we got two different results,  
> attached herewith (where lines are deleted in the text; one can ask for complete output). For example, 
> in the output file h2cs_opt-fixed.out, the optimized coordinates are:
> 
> Atomic Coordinates
> 
>   Nr  Atom  Charge       X              Y              Z
> 
>    1   H1    1.00    0.000000000    1.765967499   -2.745177896
>    2   H2    1.00    0.000000000   -1.765967499   -2.745177896
>    3   C      6.00    0.000000000    0.000000000   -1.634732411
>    4   S    16.00    0.000000000    0.000000000    1.455909829
> 
> On the other side, the optimized coordinates in the output file H2CS_opt2.out are:
> 
> Atomic Coordinates
> 
>   Nr  Atom  Charge       X              Y              Z
> 
>    1   H1    1.00    0.000000000    1.765973450   -3.050725593
>    2   H2    1.00    0.000000000   -1.765973450   -3.050725593
>    3   C      6.00    0.000000000    0.000000000   -1.940275913
>    4   S    16.00    0.000000000    0.000000000    1.150376265
> 
> There is large difference. Could you please suggest me some reason for the
> difference between the two outputs.
> 
>  With regards,
>  
> Prof. Suresh Chandra,
> 
> Deputy Director & Professor,
> Amity Centre for Astronomy & Astrophysics,
> Amity Institute of Applied Sciences,
> Amity University, Sector-125, 
> NOIDA 201313, U.P., India
> 
> Email: schandra2 at amity.edu;
>        suresh492000 at yhoo.co.in
> 
> Mob. +91-9818005663, 8368908608
> =========================================
> Alexander von Humboldt Fellow (Germany),
> Former Director, School of Physical Sciences,
> S.R.T.M. University, Nanded (Maharashtra)
> <h2cs_opt-fixed_modified.out><H2CS_opt2_modified.out>_______________________________________________
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--
Prof. Peter J. Knowles             
School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
Telephone: +44 29 208 79182
Email: KnowlesPJ at Cardiff.ac.uk 

Yr Athro Peter J. Knowles
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Prif Adeilad, Plas y Parc
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Ebost: KnowlesPJ at Caerdydd.ac.uk
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