[gmx-users] how do position restraints work??

[Vivek Raut]

is fixing the atoms ( by defining a fixgroup in the .ndx file & then fixing 
that group in x, y, z directions. . eg: freezegrps = BACKBONE     freezedim 
= Y Y Y )  same as introducing the positional restraints to the molecules 
by adding ( define = -DPOSRES ) in the .mdp files???

i tried to follow the second method, but when i see the simulation through 
VMD software, all the restrained molecules still change their position. why 
is that???.


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Vivek Raut
Graduate Research Assistant
Department of Bioengineering
Clemson University
Clemson, SC- 29631. USA
Email: vraut at clemson.edu
Phone: 864-650-1431
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