md on peptide single copy
 &cntrl
  ntx=7, irest=1,
  ntf=2, ntc=2, ntpr=1, 
  nstlim=20, dt=0.001,
  ntb=1, ntp=0, temp0=300,
  nscm=0,
  ntwx=100, ntwr=20, ntpr=20, dt=0.002, iwrap=1,
 /

