I’ve had a few questions about the achemso bundle concerning creating references such as ‘Figures 1 to 3’ automatically. The problem has been that I’ve been using the varioref package to turn \ref{some-fig} in ‘Figure 1’ automatically, rather than having to put Figure~\ref{some-fig}. Unfortunately, varioref does not handle multiple references in an automated fashion.
For version 3.4 of achemso (which I’ve just sent to CTAN), I’ve switched to the cleveref package. This means that you can now write something like \ref{fig-1,fig-2,fig-3} and get ‘Figures 1 to 3’ without further effort. I hope that this makes life much easier for users, although it does mean that there is another package required to use achemso. I think that this is the right balance: I’m sure users will let me know if I’ve got it wrong.