# [gmx-users] MBAR issue

gozde ergin gozdeeergin at gmail.com
Fri Nov 11 09:04:38 CET 2016

Dear all,

I follow James Barnett tutorial of “Methane Free Energy of Solvation” however I use betaine molecule other than methane.
In order to analyse the data I use alchemical_analysis.py code however I get an error :

pymbar.utils.ParameterError: Warning: Should have \sum_k N_k W_nk = 1.  Actual row sum for sample 0 was 1.307134. 663638 other rows have similar problems

Do you have any idea about the error or anyone here face with this error?