[gmx-users] Simulation of a charged system

[Surya Prakash Tiwari]

Dear Gromacs users,

I am simulating a charged system with periodic boundary conditions. My
system has 506 water molecules and one ion.
I am trying to calculate the free energy of an ion.
I do not want to use any counter-ions to neutralize the system,
because I don't have force-field between my ion and the counterion.

In particular, I want to reproduce the following paper: 
Horinek, D., Mamatkulov, S. I., & Netz, R. R. (2009). Rational design
of ion force fields based on thermodynamic solvation properties. The
Journal of chemical physics, 130(12), 124507. doi:10.1063/1.3081142

Their system is also charged, has one ion and 506 water molecules.
They are using AMBER software. On page number 7, they have discussed
the correction terms due to ewald summation (equation 6) in a charaged
system.
On the same page, they further say that AMBER has implemented first
term in eqn. 6 to account for ion’s Coulomb interaction with its
periodic images:
"In the PME implementation in AMBER, a self-energy correction of
N*e^2 *xi /(8*pi*epsilon) is already accounted for."

I just want to know whether, Gromacs has the same implementation in
their PME to account for ion’s Coulomb interaction with its periodic
images.

Thanks in advance.

Regards,
Surya Prakash Tiwari