fully implemented for ratio <-> abundance
also implement for abundances --> ... --> deltas and back (this is important for exact mass balance calculations)
think about appropriate ways to do fractionation factor * ratio/delta value in an entire isotope system
fully implemented for ratio <-> abundance
also implement for abundances --> ... --> deltas and back (this is important for exact mass balance calculations)
think about appropriate ways to do fractionation factor * ratio/delta value in an entire isotope system