[gmx-users] Misunderstandings with g_rms

[DimitryASuplatov]

Hello,

I am sorry for this stupid question.

Lets say I have an index file of all chain A atoms. I want to calculate
RMS of chain A _backbone_ only.

I run g_rms. It asks two questions:
1/ Select group for least squares fit
2/ Select group for RMSD calculation

To the best of my understanding, I should answer "BACKBONE" to the first
question and enter group number corresponding to chain A index file to
the second one.

Is that correct?
Thank you. 
SDA