 Testing tutorial on website for QMMM with Gaussian 
 &cntrl
  imin=0,nstlim = 0,	!do not run a minimization or MD run
  ntb=2,		!constant pressure periodic boundary conditions
  ntf=2,ntc=2,
  cut=10.0,		!8 ang classic bond cutoff
  ntp=1,
  ifqnt=1		!switch on QM/MM
 &end
 &qmmm
  qmmask='@16-30',
  qmcharge=0, 
  qm_theory='EXTERN',
  qmcut=10.0,
  qm_ewald = 0 !Use a real-space cutoff for QM-QM and QM-MM long range interactions.
 &end
 &gau
   method = 'B3LYP',
   basis = '6-31G* Freq',  
 &end


