Firefly and PC GAMESS-related discussion club


 
Learn how to ask questions correctly  
 
 
We are NATO-free zone
 



Re: MP2 - EFP Energy

Alex Granovsky
gran@classic.chem.msu.su


Hello,

Does this output come from GAMESS (US)?
I do not know details on GAMESS (US) implementation of MP2-EFP so you may need to ask GAMESS authors directly.

Nonetheless, I think your result are correct. If you look at this:

>        STATIC INTERFRAGMENT ENERGY =      -5.1078075649
>            FRAGMENT-NUCLEAR ENERGY =      -0.4524465268
>    TOTAL FRAGMENT INDUCTION ENERGY =      -2.0717456091

you will see that interfragment interaction accounts for ca. 7 Hartree. It seems it is simply added to the total energy.

Kind regards,
Alex Granovsky


On Tue Apr 15 '14 9:16pm, Rahul Singh wrote
-------------------------------------------
>Hello Everyone,

>           I have been doing simulations in vacuum and in water for a certain molecule. I have modeled the water using EFP and have used MP2 for the ab-intio calculations. Now, when I am comparing the energies of the molecule in water and in vacuum, the difference in energy is very large and comes around ~ 7 hartrees. This large difference has not been reported in previous papers but of course nobody has used MP2-EFP combination. So, please tell me which energy is correct and should be compared with the energy in vacuum. The three options which I see in the log file are :

>Energy = Solute potential energy + Solute kinetic energy      or
>Energy = Total Energy   or
>Energy = Total Energy - Effective Fragment Energy

>This is how the energy values look like in an MP2-EFP calculation

>                ONE ELECTRON ENERGY =   -5521.7840543068
>                TWO ELECTRON ENERGY =    2405.7150238918
>           NUCLEAR REPULSION ENERGY =    2049.8047313555
>          EFFECTIVE FRAGMENT ENERGY =      -7.6260095839
>                                      ------------------
>                       TOTAL ENERGY =   -1073.8903086434

> ELECTRON-ELECTRON POTENTIAL ENERGY =    2405.7150238918
>  NUCLEUS-ELECTRON POTENTIAL ENERGY =   -6587.0748922130
>   NUCLEUS-NUCLEUS POTENTIAL ENERGY =    2049.8047313555
> ELECTRON-FRAGMENT MULTIPOLE ENERGY =       0.4295428235
> ELECTRON-FRAGMENT REMAINDER ENERGY =      -0.0600891940
>        STATIC INTERFRAGMENT ENERGY =      -5.1078075649
>            FRAGMENT-NUCLEAR ENERGY =      -0.4524465268
>    TOTAL FRAGMENT INDUCTION ENERGY =      -2.0717456091
>                                      ------------------
>             TOTAL POTENTIAL ENERGY =   -2138.8176830370
>                                      ------------------
>            SOLUTE POTENTIAL ENERGY =   -2131.5551369657
>              SOLUTE KINETIC ENERGY =    1064.9273743936
>                 VIRIAL RATIO (V/T) =       2.0015967175
>
>
>
>
>
>


[ Previous ] [ Next ] [ Index ]           Wed Apr 16 '14 12:20pm
[ Reply ] [ Edit ] [ Delete ]           This message read 538 times