Ion Pair Gibbs Ensemble Transfers

Hello,

I would like to have a Gibbs ensemble (2 box) system with 3 species: one which cannot transfer between boxes, and +/- salt ions, the ions of which are capable of swapping between boxes. Does Cassandra support ion pair swaps between boxes (to maintain electroneutrality in a swap)? I cannot find anything in the manual about pair swaps, only single atom swaps.

Thanks very much for your help!

Best,

Nick Jackson

Hi Ryan,

Thanks for the response! If the addition would be relatively straightforward, I have a lot of interest in working on the development version. Indeed, swapping pairs should have a low acceptance probability and only really work at low densities ( scitation.aip.org/content/aip/journal/jc.../11/10.1063/1.439092 ), but it's between that and transferring single ions between boxes and not having electroneutrality for the Ewald sum after a successful transfer.

For high densities, one could make the non-ion solvent explicit and then try a semi-grand gibbs ensemble swap between boxes. That may be a better route.

Very Best,

Nick