Mixtures of methanol with water and ammonia dominate the chemistry of cometary bodies, leftovers of the building blocks of the outer planets. We have previously determined the structure of methanol monohydrate from powder data collected on HRPD and now propose to study the two ammoniates of methanol using the same techniques. The phase diagram already hints that the ammoniates have fully 3D hydrogen bonded networks, unlike the monohydrate which is only H-bonded in two dimensions. Determining the structures of these two compounds will advance our understanding of weak hydrogen bonding, and will require the collection of a full structural data set from each, as well as a temperature scan to search for order-disorder transitions, such as we have seen in the monohydrate.