Andrius Merkys

> As I've written in other issues/commits, I very much like the idea of standardizing `fractional_site_positions`. But I realize now with this PR in hand that if we do it...

I prefer keeping the PR open as well. Once closed, a PR becomes virtually invisible and it is easy to forget it, scrapping all the effort.

In the web meeting of 2020-10-28 the following points were raised: * isotopes can already be identified via atomic masses, therefore, there is no need to duplicate that information in...

> * isotopes can already be identified via atomic masses, therefore, there is no need to duplicate that information in chemical names Actually, the specification defines `mass` as an average...

> Would it make sense to change the value of `mass` to a list instead? If the average value of the mass on the site is needed it can easily...

With #344 merged and staged for release in v1.0.1, deuterium and tritium can be removed from the `species` and probably formulae too. Nevertheless there is an advantage of retaining their...

I am just thinking out loud about this scenario. Not sure how useful it is, though. But since by converting D and T to H in COD/TCOD we lose some...

> I am however wondering what counts as a minute amount. In my proposal I meant > 0. So if element exists in the structure, it has to be mentioned...

> For experimental systems it could be more problemetic as a material can have impurities and defects. In that case a material may have a composition like Ca198Na2O199 Do we...

> > Fair enough. This can be achieved now by querying elements HAS ONLY [ "Ca", "O" ] no matter what conventions for formulas are used. > > This would...