qmmm

This option controls the quantum mechanics/molecular mechanics (QM/MM) calculation details.

qm_region

Value	Atom range
Default	None

Define the atoms in the QM region.

qmmm
  qm_region 1-14 16 23 45-48
end

In this input, atom 1,2,3,4,5,6,7,8,9,10,11,12,13,14,16,23,45,46,47,48 will be treated with QM methods, and others will treated with MM methods.