## Firefly and PC GAMESS-related discussion club

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** Re: Adding the coordinates from the first Optimization run to the next calculation..... **
Solntsev Pasha

solntsev@univ.kiev.ua

Dear Siddheshwar.Why don't you want just copy the coordinates manually from output file? Why do you need to use MASK?

To start HESSIAN calculation you need the last coordinates and probably orbital vectors ($VEC) from PUNCH file. Select $guess guess=moread norb= $end. Consult manual for explanation.

Temperature is not involved in vibration degree of freedom. It means, to calculate thermodynamic properties for N temperatures you need to do hessian only once and then use that data to calculate thermodynamic functions for N temperatures.

BTW, you can check "datagam" tool (check "Related" section of this page) to extract $VEC from you punch file, and probably last coordinates as well.

Best,

Pavel.

On Thu Dec 27 '12 9:50am, Siddheshwar Chopra wrote

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>Dear Prof. Alex,

>This is in regard to performing Hessian Calculations. I have the output file obtained after successful Optimization. I wish to know the following things:

>1) Are the coordinates available after the line "Equilibrium geometry located", the optimized coordinates? So can I copy paste them directly onto the file which would be used for the Hessian calculations in my next run? I use MASK to save the output file as the input file.

>2) Is the above step sufficient enough to start the hessian calculation? Or do i need to copy the Initial guess from the PUNCH file too?

>3) If I wish to calculate the thermodynamical properties for different temperatures (say 3 temps.), than does the Firefly perform Hessian calculations 3 times, OR it just calculates the new 3 sets of properties from the properties obtained at T=298K?

>Regards,

Thu Dec 27 '12 7:21pm

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