Minimization of the entire molecular system
 &cntrl
  imin=1,
  maxcyc = 25000,
  ncyc   = 250,
  ntr    = 1,
  cut    = 12,
  ntb=0,igb=1,
  ntpr=5,
  drms=0.005,
 &end
Keep Ca fixed with weak restraints
2.0
FIND
CA * * *
SEARCH
RES 1 247
END
END