[gmx-users] peptide's COM distance to top of a slab

[Alexander Alexander]

Dear gromacs user,

I have peptide getting adsorbed into a solid surface, I can get the
distance between COM of peptide and COM of the slab by below command,

gmx distance -n index.ndx -select 'com of group Other plus com of group
Protein' -f noPBC.xtc -s prd.tpr -oxyz disxyz.xvg -tu ns

I was wondering if a similar command is available to get the distance
between peptide's COM and top of the slab?

Regards,
Alex