[gmx-users] Umbrella sampling Tutorial Fatal Error

[Nima Soltani]

Hi Dear Gromacs Users
I am following umbrella sampling tutorial provided by Dr Justin Lemkul
(This tutorial is not updated for Gromacs 5 However I am using Gromacs
5.0.2 and i am trying my best to use files and commands compatible with
version 5)

I have done all the parts up to pulling section very well
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin/gmx-tutorials/umbrella/05_pull.html
but at the stage that I want to generate pull.tpr file it gives me a fatal
Error:
"Fatal error:
Group pull_group1 required by grompp was undefined."
I Checked spelling of "Chain_A" that i named, utilizing "mgx make_ndx"
command at previous step
Any advice or guidance would be greatly appreciated
Best Regards,
Nima Soltani
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Graduate Student of Physical Chemistry
Department of Chemistry,
Sharif University of Technology.
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