We generated Pymatgen code for each crystal structure in the dataset. We employed the method from_spacegroup and extracted the necessary parameters from a serialized structure representation: space group, lattice vectors, lattice angles, atoms, and fractional atomic site coordinates. In CIFs, these parameters are typically stored as numbers with up to 16 decimals. Research shows that while LLMs utilize encoded number values for calculations, their compression may not be lossless, leading to errors in subsequent computations, particularly with large input numbers . To reduce the sequences of numbers in the code, we rounded the lattice vectors to 2 decimals, and the lattice angles to 0 decimals. For the site coordinates, we saved them as fractions if they matched a rational approximation up to 4 digits of p/q for p,q ∈ {1,2...100}. If not, we used decimals with 4 digits. (We note that other work has explored simplifying text descriptions of bond angles or distances using specialized tokens, which could be adapted to handle repeating decimal values, but we did not perform this here.) This rounding does results in a structure which is slightly different from the original serialized structure. We provided text comments to each line of code with reasoning for the choice of code parameter values. Both commented and uncommented codes are available.