[h5md-commit] subsystems with varying number of particles

[Felix Höfling]

Hi,

In commit a3ee98a, the fill value of the particle ID has been given a
meaning which I find very useful.

Just one question: what if there is no fill value defined? Does
H5Pget_fill_value() return the default value? I think it is 0 for Integer
types, which would conflict with regular particle IDs starting at 0.

Is this an issue that needs to be addressed somehow?

Felix