The documentation of PBEQ module indicates that the two parameters, HTMEMB and EPSH, represent the thickness and the dielectric constant of the headgroups of lipid bilayers, respectively. It seems that CHARMM c29b2 and c30b2 does not recognize HTMEMB; EPSH seems to have no effect on the electrostatic free energy. Does any one know if these two parameters are implemented in later version of CHARMM? Is EPSH a dumb parameter?
Both CHARMM c30b2 and c29b2 give the following message when assigning a value for HTMEMB
**** Warning **** The following extraneous characters
were found while command processing in PBEQ
Thanks for your time and effort