Dilute.m

Splits the spin system into several independent subsystems, each containing only one instance of a user specified isotope that is deemed "dilute". All spin system data is updated accordingly and basis set information, if found, is destroyed. Syntax:

             spin_systems=dilute(spin_system,isotope)

where isotope is a character string specifying the isotope to be treated as dilute. A cell array of spin_system objects is returned, with each cell corresponding to one of the newly formed independent isotopomers.