We really like tbhe directionb that your going, and that you understand that the 2 is subscript. Can you play with more lively color options? Making a blue and green hybrid, maybe doing some gradients within the colors.
What about designing on a black background and changing the logo colors to be white/blue/lime green in nature.
Also, I would like to mention that I really like the design of the molecular structure too. can you play with that in a little more subdues wire frame?