Hello Amber Users
I am using Amber 9 for my anal interaction energies calculations
I want to Calculate the interaction energy between a water molecule and a
monomer of a homo dimeric protein.
 I used the following input file
  1    0    0    0    0    1
   0  0.0  0.0  0.0   0.0
   7    0    0    0    0    0
 99.0      2.0       1.2       1.0
   1 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0
ENERGY
 first residue
RES 1 50 ..............................
......................................................
which correponds to one monomer
END
 second residue (or group of atoms)
RES 200
.........................................................................................
water molecule
END
END
STOP
These dotted line is just for representation only
NOw the output file which i got from this shows the interaction energy as
follows :
          TOTAL INTERACTION ENERGY MATRIX
            1          2          3
    1   -2813.486     -0.463   -457.911
    2      -0.463      0.000    -17.139
    3    -457.911    -17.139  -3101.484
          INDIVIDUAL GROUPS INTERACTION
     GROUP      INTRA      INTER      TOTAL
         1   -2813.49    -458.37   -3271.86
         2       0.00     -17.60     -17.60
         3   -3101.48    -475.05   -3576.53
     TOTAL   -5914.97    -475.51   -6390.48
Few days back I got an answer from the archive that group 3 in  the
interaction matrix corresponds to the left up residues which i did not
mention in the input file
So if that is the case than the interaction energies between the group 3 & 1
and group 2 & 1 should be same in this particular case or even if difference
will be there it should not be suc h high value since I am calculating the
interaction of water with the monomer of a homodimer so with respect to
other also the energy should be almost  (if not exactly) similar.
Please suggest me something
what is group 3 actually if I am wrong or if not what else could be the
reason for the descripency.
Note : cut off is not all responsible I have checked at different cut off
values The value I am getting is always same
Waiting for your reply
Thanks & Regards
Gurpreet
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Received on Sun Oct 21 2007 - 06:07:12 PDT