[gmx-users] total energy of system is positive,MD normal ?

[Mark Abraham]

linfu wrote:
> Dear all!
> 
> My Simulation was done in decane and dmso. during analysis(g_energy), i find the energy of the whole system is positive
> not negative.however, fluctuation of temperature ,pressure and total energy is normal. Could anyone help me to figure out
> whether this MD is normal or not!
> Thank you in advance!

Well that totally depends on your forcefield. If your system does not
have enough favourable long-range interactions then the energy will
perforce be positive. This would also happen if your system was so dense
you were in the steep part of your L-J functions.

Mark