! Basic Langevin dynamics parameters
      logical surfarea
      integer reset_fricmat
      double precision scal_fric,rwat,etawat,gamp,
     & gamsc(ntyp1),stdfp,stdfsc(ntyp),stdforcp(MAXRES),
     & stdforcsc(MAXRES),pstok,restok(ntyp+1),cPoise,Rb
      common /langevin/ pstok,restok,gamp,gamsc,
     & stdfp,stdfsc,stdforcp,stdforcsc,rwat,etawat,scal_fric,
     & cPoise,Rb,surfarea,reset_fricmat
! Variables used in Langevin dynamics calculations
      double precision friction(3,0:MAXRES2),stochforc(3,0:MAXRES2),
     & fric_work(MAXRES6),stoch_work(MAXRES6),fricgam(MAXRES6),
     & DMfric(MAXRES2),DU1fric(MAXRES2),DU2fric(MAXRES2)
      logical flag_stoch(0:maxflag_stoch)
      common /langforc/ friction,stochforc,DMfric,DU1fric,DU2fric,
     & fric_work,fricgam,stoch_work,flag_stoch