About data/split.sh:

When you run it, it will create the following directory tree inside split:

• formula-name
  • train
    • formula
    • name
  • test
    • formula
    • name
• formula-inorganic-organic
  • train
    • inorganic
    • organic
  • test
    • ...
• name-inorganic-organic
  • train
    • ...
  • test
    • ...

Then, it will split the data read from source into single-line files and place them inside the final directories.