*>>>>>>       SOD and CLA Ions Topology File           <<<<<<<<<
*extracted from
*>>>>>>>>CHARMM22 All-Hydrogen Topology File for Proteins <<<<<<
*>>>>>>>>>>>>>>>>>>>>> August 1999 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<
*>>>>>>> Direct comments to Alexander D. MacKerell Jr. <<<<<<<<<
*>>>>>> 410-706-7442 or email: alex,mmiris.ab.umd.edu  <<<<<<<<<
*
27  1

!
! references
!
!IONS
!
!all ions from Roux and coworkers
!
!Sodium
!
!Beglov, D. and Roux, B., Finite Representation of an Infinite
!Bulk System: Solvent Boundary Potential for Computer Simulations,
!Journal of Chemical Physics, 1994, 100: 9050-9063
! 
! VdW radii from http://www.webelements.com (Ca scaled using atom radius)
! 
! THESE MUST BE IN SYNC WITH ION DEFINITIONS IN meadionize.tcl

MASS   1   SOD  22.989770 NA ! Sodium Ion
MASS   2   POT  39.102000 K  ! Potassium Ion
MASS   3   MG   24.305000 MG ! Magnesium Ion
MASS   4   CAL  40.078000 CA ! Calcium Ion
MASS   5   CLA  35.450000 CL ! Chloride Anion

RESI SOD          1.00 ! Sodium Ion (R_vdw = 2.27A)
GROUP
ATOM SOD  SOD     1.00
PATCHING FIRST NONE LAST NONE
 
RESI POT          1.00 ! Potassium Ion (R_vdw = 2.75A)
GROUP
ATOM POT  POT     1.00
PATCHING FIRST NONE LAST NONE

RESI MG           2.00 ! Magnesium Ion (R_vdw = 1.73A)
GROUP
ATOM MG   MG      2.00
PATCHING FIRST NONE LAST NONE
 
RESI CAL          2.00 ! Calcium Ion (R_vdw = 2.08A - scaled from www.webelements.com)
GROUP
ATOM CAL  CAL     2.00
PATCHING FIRST NONE LAST NONE
 
RESI CLA         -1.00 ! Chloride Anion (R_vdw = 1.75A)
GROUP
ATOM CLA  CLA    -1.00
PATCHING FIRST NONE LAST NONE