I want to do a simple algebraic calculation in CHARMM involving floating point numbers. For example, say I want to assign floating point values to variables a,b and c and d and then assign the value of a*b+c/d to e. Is there a direct way to do this? I have tried using calc but it doesn't seem to work, I get "error in conversion" warnings. I am not pasting my input/output file sections as I think this is a very general question but I can do so if further clarification is required. Any help will be greatly appreciated, Thanks!