[gmx-users] gmx distance

[Pandya, Akash]

Hi all,

I'm trying to calculate the distance between two groups using the following command line:


gmx distance -f md_0_1.xtc -s md_0_1.tpr -oav distance.xvg -select `com of group "1" plus com of group "14"`


Group 1 is my protein and Group 14 is my ligand. There is an error message that shows up:

Inconsistency in user input:
Selection 'Protein' does not evaluate into an even number of positions (there
are 6617 positions)

I'm not sure how to solve this problem. Does anyone have a solution?