From: Jérôme Hénin (
Date: Mon Feb 18 2019 - 16:44:16 CST

Hi Amy,

thank you for your report. To help us figure this out, we'd need the
original fepout files. You can send them off-list if necessary.


On Mon, 18 Feb 2019 at 22:57, Amy Rice <> wrote:

> Hi all,
> I noticed that using different versions of ParseFEP (1.9.2 vs 2.1) gives
> different free energy output when supplied with the same fepout files and
> temperature selection. With 1.9.2, the free energy change was calculated as
> -89.320 with a total error of 0.099. The same files in version 2.1 resulted
> in a free energy change of -98.704 and a total error of 0.071. Is this
> expected behavior? In both cases, I set the temperature to 310 K and
> selected to use the BAR-estimator method. Was there a change in how the
> calculation is performed between these two versions? It is a little
> disconcerting to have such a large difference between the two. I have
> attached the log file for both cases.
> Best,
> Amy
> --
> Amy Rice
> Ph.D. Candidate
> Physics Department
> Illinois Institute of Technology