special <xray-special-statement> end

<xray-special-statement> :==

  selection=<atom-selection>
  --{Atom selection.}
  to=<atomic-object>
  --{Destination for multiplicity. The multiplicity for the selected
     atoms is calculated and stored in <atomic-object>. Atoms at general
     positions are indicated by a 1, atoms at special positions are indicated
     by a multiplicity > 1, and unselected atoms are indicated by 0.}