One of "5OH" (default), "5PPP-3P", or "5PPP-3OH" describing 5' and/or 3' modifications of the fragment
adduct
One of 'Na', 'K', or '' (default) specifying whether or not the molecular weight should be calculated for a salt adduct
rxn
One of 'T' or 'C' indicating which cleavage reaction is employed to generate the fragment
Value
Returns a numerical output corresponding to the molecular weight (in Da) of sequence input. Note that the output may actually represent multiple molecular weights
if/whenever the input sequence contains one or more degenerate bases (e.g. R or Y).