Make Your Own Atmosphere
I remember hearing at some point David Lee Roth (AKA Diamond Dave, original singer of Van Halen) saying people are always out prowling around saying, "Where's the action?" and his saying in response, "Man, you ARE the action!"
Atmosphere and environment are big elements of successful lifting, but you can't expect to just stumble upon them in some secret location. You ARE the atmosphere and YOU make the environment what it is. If you train alone, this is very obvious. If you train in a group, take the initiative and create the atmosphere - set the example for others to follow to create the ideal training environment. Don't wait around for it to magically appear - it never will.
Atmosphere can be influenced in part by the physical environment - for example, a clean, well-lit, spacious gym feels much different than a small, cramped, dirty, windowless basement gym - but it's the people inside it who truly create the atmosphere. That basement gym can be as depressing as you let it be, or it can be full of energy. Likewise, that big, airy gym can be nice, but if it's filled with unenthusiastic, boring people, it's going to be depressing.
Act the way you want your training partners to act. Display the energy and attitude you want to see in the gym. If nothing different is being actively enforced and reinforced, you will change the atmosphere into what you want.
If you're a coach, the creation and reinforcement of the proper atmosphere is ultimately your responsibility. This means setting an example for your lifters with regard to energy, attitude and behavior, and enforcing your rules with your lifters. This can be as severe as removing athletes who don't comply. In any case, how your lifters behave and the kind of atmosphere they create in your gym is something you'll always need to monitor and will likely require your periodic intervention.