Exception: sum = 0

For instances of even <= 14, specifically 10 nodes, using this code always returns the above exception. It seems for certain values which are quite small, the sum == 0 check for this exception is triggered even though the value is not 0. This is however not consistent, since I found that values such on the order of 10^-5 and 10^-6 do not trigger this, but values like 0.00017 do. Any suggestions?
