As well as the editing “Residue Info” to change occupancies of individual atoms, one can use a scripting function to change occupancies of a whole residue range:
(zero-occupancy-residue-range imol chain-id
resno-start resno-last)
example usage:
(zero-occupancy-residue-range 0 "A" 23 28)
This is often useful to zero out a questionable loop before submitting for refinement. After refinement (with refmac) there should be relatively unbiased density in the resulting 2Fo-Fc-style and difference maps.
Similarly there is a function to reverse this operation:
(fill-occupancy-residue-range imol chain-id
resno-start resno-last)