gctacgttataaagct: baseline for QM/MM no water or Na+ in QM
 &cntrl
  imin=0, ntb=1
  cut=10.0, ntc=2, ntf=2,
  tempi = 310.15, temp0 = 310.15,
  ntt = 3, gamma_ln = 1.0,
  nstlim=0, dt=0.002,
  ntpr=1, ntwx=1, ifqnt=1
 /
 &qmmm
  qmmask=':4-13,20-29',
  qmcharge=-18,
  qm_theory='EXTERN',
  qmshake=0,
  qm_ewald=0,
  writepdb = 1
 /
 &qc
   method = 'BLYP',
   basis = '6-31G*',
 /

