https://github.com/dftd3/simple-dftd3/blob/442fbec1b0cf249359358ed247d90731d4da4b37/python/dftd3/ase.py#L124 Presumably that should say D3 and not D4. If you search "D4" you'll see a bunch of other instances: https://github.com/dftd3/simple-dftd3/blob/442fbec1b0cf249359358ed247d90731d4da4b37/python/dftd3/pyscf.py#L195
simple-dftd3/python/dftd3/ase.py
Line 124 in 442fbec
Presumably that should say D3 and not D4.
If you search "D4" you'll see a bunch of other instances:
simple-dftd3/python/dftd3/pyscf.py
Line 195 in 442fbec