Re: [gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

2013-06-05 Thread Michael Shirts
for GROMACS users Subject: Re: [gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field Things should be identical - any quantity computed from a zero charge has to be zero :-). Mark On Thu, May 30, 2013 at 1:26 PM, Dr. Vitaly Chaban vvcha...@gmail.comwrote

RE: [gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

2013-06-04 Thread Dallas Warren
. -Original Message- From: gmx-users-boun...@gromacs.org [mailto:gmx-users- boun...@gromacs.org] On Behalf Of Mark Abraham Sent: Thursday, 30 May 2013 9:32 PM To: Vitaly Chaban; Discussion list for GROMACS users Subject: Re: [gmx-users] Difference between the electrostatic treatments PME/Cut

Re: [gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

2013-05-30 Thread Mark Abraham
No charges = no problem. You can trivially test this yourself with mdrun -rerun ;-) Manual 4.1.4 talks about what RF is doing. Mark On Thu, May 30, 2013 at 6:38 AM, Dallas Warren dallas.war...@monash.eduwrote: In a system that has no charges, should we observe a difference between

Re: [gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

2013-05-30 Thread Dr. Vitaly Chaban
Hmmm... And what does the observed difference look like, numerically? On Thu, May 30, 2013 at 10:14 AM, Mark Abraham mark.j.abra...@gmail.comwrote: No charges = no problem. You can trivially test this yourself with mdrun -rerun ;-) Manual 4.1.4 talks about what RF is doing. Mark On

Re: [gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

2013-05-30 Thread Mark Abraham
Things should be identical - any quantity computed from a zero charge has to be zero :-). Mark On Thu, May 30, 2013 at 1:26 PM, Dr. Vitaly Chaban vvcha...@gmail.comwrote: Hmmm... And what does the observed difference look like, numerically? On Thu, May 30, 2013 at 10:14 AM, Mark

RE: [gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

2013-05-30 Thread Dallas Warren
the electrostatic treatments PME/Cut-offs and Reaction Field Things should be identical - any quantity computed from a zero charge has to be zero :-). Mark On Thu, May 30, 2013 at 1:26 PM, Dr. Vitaly Chaban vvcha...@gmail.comwrote: Hmmm... And what does the observed difference look like

[gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

2013-05-29 Thread Dallas Warren
In a system that has no charges, should we observe a difference between simulations using PME/Cut-offs or Reaction Field? From my understanding there should not be, since there are no charges which treatment you use shouldn't' make a difference. However, it does and I am trying to work out