[gmx-users] Positive Coul. recip. term

[Denny Frost]

Dear all,
I am trying to equilibrate a solvent of pure ionic liquid.  The system
keeps exploding (after 2-5 ns) and I am not sure why, though I believe
coulombic interactions are to blame.  This is because the Coul-SR term is
negative, but the Coul. recip term is very positive throughout the entire
run (giving the entire system a positive potential energy).  I think this
means that the short-range electrostatics are okay, but the long range
electrostatics (calculated with PME) are not.  Does anybody have any
suggestions as to why this would happen?  I have used the exact same PME
input parameters for another ionic liquid that works just fine.  They are
listed below.

rcoulomb = 1.2
fourierspacing = 0.12
pme_order = 4
ewald_rtol = 1e-5

Thanks!
Denzil Frost
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