<div style="font-family: 'Times New Roman'; font-size: 16px;">Hello everyone,<br _moz_dirty="" /><br _moz_dirty="" />I've been performing some rather long simulations (400ns) of a short peptide chain in explicit TIP4P water solvent using opls-aa forcefield with ionic concentrations near 1M, and I am finding a lot of "clustering" of my ionic species. Has anyone else run into this type of problem? I am running NPT with a temperature of 283K with berendsen coupling. For electrostatics iI am using PME, which I have been told works welll with ions in solution. The clustering of the ions reminds me of a crystallization process, this just doesn't feel like it's physical.<br _moz_dirty="" /><br _moz_dirty="" />Thanks in advance.<br _moz_dirty="" /><br _moz_dirty="" />Micholas D. Smith <br _moz_dirty="" />Graduate Student<br _moz_dirty="" />Drexel University<br /></div>