Constant Volume Minimization 3 with backbone fixed
 # Control section
 &cntrl
  imin=1,
  irest = 0,
  ntmin = 1, maxcyc = 20000, ncyc = 10000, dx0 = 0.01, drms = 0.0001,
  cut = 10.0,
  ntb = 1,
  ntp = 0,
  ntr = 1, restraintmask=':1-612 & @CA,C,O,N,H', restraint_wt=10.0
  
 /
