Why not protein is not come in the selection

User discussions
1

gmx rmsf -s em.tpr -f md_0_10_center.xtc -n index.ndx -o rmsf.xvg
:-) GROMACS - gmx rmsf, 2026.0 (-:

Executable: /usr/local/gromacs/bin/gmx
Data prefix: /usr/local/gromacs
Working dir: /mnt/d/vchemistry2
Command line:
gmx rmsf -s em.tpr -f md_0_10_center.xtc -n index.ndx -o rmsf.xvg

Reading file em.tpr, VERSION 2026.0 (single precision)
Reading file em.tpr, VERSION 2026.0 (single precision)
Select group(s) for root mean square calculation
Group 0 ( System) has 18 elements
Group 1 ( Other) has 18 elements
Group 2 ( LIG) has 18 elements
Group 3 ( System_&!H*) has 12 elements
Select a group: 3
Selected 3: 'System&_!H*’
Last frame 1000 time 10000.000

Can you please help me why not protein or backbone not come in the selection ? Please help me to find the proper command

2

If you pass an index with -n index.ndx then you will be prompted with the contents of that index file. Take away that flag and you should get the standard selection options for proteins from GROMACS.