Conrad Chan

Same problem also occurs for HDF5 outputs, so it is not specific to native outputs.

> How similar do you expect the results to be given machine rounding, etc...? It should be possible for results to be bitwise identical after restarting from an output. Indeed,...

> about 10^-15 is the typical tolerance for diffdumps, this is something not being done right in the MPI code. Just to clarify, this has nothing to do with MPI....

One contribution to this error is that `h` is stored in single precision, so the starting point for density iterations is different after a restart. But this contribution is probably...

Would you consider writing "restartable" files infrequently that contain `h` in double precision and the forces? E.g. once every 24h of wall time? And perhaps it could be optional, so...