Defined in file omssa.asn
C++ class: CMSMZHit

        ion MSIonType,  -- ion type, e.g. b
        charge INTEGER, -- ion charge
        number INTEGER, -- the sequential number of the ion
        mz INTEGER,              -- scaled m/z value in Da
        index INTEGER OPTIONAL,  -- the index of the peak in the original spectrum
        moreion MSIon OPTIONAL,  -- more information about the ion type
        annotation MSIonAnnot OPTIONAL   -- annotations on the ion