Re: [gmx-users] Test particle insertion change in energy - group cut off scheme

2018-03-03 Thread Arun Srikanth
I see. Thank you. I understand how tpi in gromacs works now. Perhaps my last question. Is there a restriction on the number of charge groups in gromacs ?. For example can it be equal to the number of atoms in the system ? How do think it will affect the performance of tpi which uses the group

Re: [gmx-users] Test particle insertion change in energy - group cut off scheme

2018-03-03 Thread Mark Abraham
Hi, Please see the reference manual for details, but the charge groups are defined in the topology however you wish (and need not have a net charge). Mark On Sun, Mar 4, 2018, 00:18 Arun Srikanth wrote: > Thank you. > > Can you please elaborate on this or clarify the

Re: [gmx-users] Test particle insertion change in energy - group cut off scheme

2018-03-03 Thread Arun Srikanth
Thank you. Can you please elaborate on this or clarify the following questions? 1. Supposing I have inserted one water molecule inside a polymer (an interconnected network with net zero charge), the electrostatic interactions should be computed between every atom of water and polymer atoms

Re: [gmx-users] Test particle insertion change in energy - group cut off scheme

2018-03-03 Thread Mark Abraham
Hi, TPI will only work if you choose the group cutoff scheme. But the impact of that difference is nearly zero. Mark On Sat, Mar 3, 2018, 22:29 Arun Srikanth wrote: > Hello all > > I was going through tpi.cpp file in the latest version of gromacs. > > I found this flag >

[gmx-users] Test particle insertion change in energy - group cut off scheme

2018-03-03 Thread Arun Srikanth
Hello all I was going through tpi.cpp file in the latest version of gromacs. I found this flag "TPI does not work (yet) with the Verlet cut-off scheme" My question: Does test particle insertion use the group cut off scheme to calculate the change in energy ? (assuming equilibrium trajectories