Gas2n-Merkury and Gas2n - The difference between programs

In the computer program Gas2n.exe in the source code, there is an exponential factor in the form exp(-B/x), and in the Gas2n-Merkury.exe the exponential factor is in the form exp(B/x). The exponential factor with a correspondingly large distances x in both cases is quantitatively equal almost to 1. But in one case, the factor is slightly smaller than 1, and in the second case is slightly greater than 1. As a consequence of this difference in the two executive programs exe shape of the orbit of a planet changes in a different way.