I have been very interested in the outline of a dictionary of systemic terms. These can be some of the most basic terms when it comes to describing companies from a systemic point of view.
Structure - It is the complex formal assumptions of a company regarding its goals and rules.
Field - I took this term from the vocabulary used in the cold war by both Marxists and Capitalists. The field is a less formal, more interactional concept. It has a quite clear ideological sense and it has to do with the way a collective life is understood and should be ruled. I wrote a post on the Two fields theory some time ago. It has also a lot to do with the Balance of Forces within an organization.
Group - It is even more interactional than the field. It has to do with with the affinities present in any formal organization. when you have coffee everyday with the same people at the office, you are behaving as a group.
Team - Has a clear purpose , that makes it different from the group, though it is clearly interactional. It is the consequence of being a member of the organization.
Accomplice - It can be the seed of the group or just can be a way of socializing without further implications.
The accomplice is the minimun unit of voluntary adherence. It can clearly be the source of leadership, which will be exercised on the other systemic constellations.