I got the following parameters from a CHARMM input script and would like to know if anyone can tell me what SWITch means and what good values are for CTONnb and CTOFnb?

NBONd CUTNb 15.0 CTONnb 14.0 CTOFnb 14.5 SWITch VSWItch -
CDIElectric EPSilon 4.0

CHARMM always gives warnings that these two are too close.
Is CDIElectric EPSilon the dielectric constant of the environment (e.g. 1 for vacumm and 80 for water)?


Tjaart de Beer