Description: A chemical system is an abstract representation of a pure substance or a mixture, being made of one or more chemical substances.
- id: substances primary key (auto-generated and unique)
- name: the name of the chemical system (autogenerated)
- composition: the composition of the system, either pur or a mixture of some type.
- identifier: a unique identifier for the system based on concatenation of the chemical substance ids with colons and ordered from lowest to highest
- refcnt: the number of references this system is reported in
- setcnt: the number of datasets this system is part of
- updated: datetime last updated