Dialog Box: Isotopes [Input menu; Control Window; Atom Types dialog]
This dialog allows you to specify isotope substitutions in up to two configurations beyond the base configuration, which is number 1.
The base configuration uses the atomic weights listed in the Atom Types dialog. For spectra 2 and 3, you specify the type numbers of all atoms whose atomic weights are to be changed. For example if S atoms with type 16 are to have atomic weight 36 instead of 32, you would enter 16 and 36.0. If more than one atomic type is substituted, for example types 16 and 116 for sulfur, both must be given.
If the Calculate box is not checked, the 2nd and 3rd spectra will be skipped.
See Isotope Configurations for complete information on isotope substitutions.