From NWChem

Example of QM/MM solvation free energy calculation input file

A total of two sampling cycles will be performed with 1000 samples per each cycle

memory total 2000 Mb
 start  clfoh
 permanent_dir  ./perm
 scratch_dir   /scratch
 md
 #this will require topology (clfoh.top) and restart (clfoh_neb.rst) files 
  system clfoh_neb
  cutoff 1.5 qmmm 1.5
  noshake solute
  isotherm
 end
 qmmm
 print low
 nsamples 1000
 ncycles 2
 end
 set qmmm:fep_geom clfoh_neb-s.xyzi clfoh_neb-e.xyzi
 set qmmm:fep_esp  clfoh_neb-s.esp clfoh_neb-e.esp
 set qmmm:fep_lambda 0.0 0.1
 set qmmm:fep_deriv .true.
 task qmmm fep