Zheyong Fan

See the PR #452

This time I only output nep.txt every 100 000 steps (also with date and time info now). I will consider adding more options later. #316

Erik said this is almost doable in [dynasor](https://dynasor.materialsmodeling.org/) and he is also improving it. @grtheaory It is better to leave this for [dynasor](https://dynasor.materialsmodeling.org/)

Any suggestion for the syntax? @erhart1 Currently, it is ``` dmp_exyz ``` How about if we want to dump other quantities, such as per-atom virial, per-atom heat current, per-atom charge...

I propose these: 1) dump all atoms ``` dump_exyz [quantity_1 quantity_2 ...] ``` 2) dump a group of atoms ``` dump_exyz [quantity_1 quantity_2 ...] ``` `quantity` can be velocity, force,...

Currently, all commands will only have at most one (the last) instance for each run. Do you have good reasons to use more within a run?

I have discussed with a few guys and we want to make it this way: ``` dump_xyz [list of quantities] dump_group # to choose a group for the dump; default...

That is, `dump_group` and `dump_file` can modify the behaviors of the `dump_xyz` in the current run. Is this a good way?

ok, all my proposed forms have not considered multiple instances of the command within a run. the `dump_group` was just used to modify the behaviors of `dump_xyz`. Now based on...

Yes, unwrapped coordinates are now available inside the code and it can be added to this dump. I am still thinking about the syntax of this keyword, and asking for...