Dear, This is Shubhrajyoti Panda, research scholar at Birla Institute of Technology, Hyderabad. I am using 6XG5 PDB ID for my work. But in this particular protein I want to show the distance between particular residues. But when I am going to show manually or through command it is showing the following error. Distance between PHE 31.A CA and GLY 15.A CA: 15.891 Distance between PHE 31.A CA and MET 16.A CA: 19.088 Distance between PHE 31.A CA and ALA 19.A CA: 15.571 Distance between PHE 31.A CA and ILE 14.A CA: 14.072 Error while sourcing chimera_distances.cmd, line 14: "distance :31.A@CA :45.A@CA" *Exactly two atoms/axes/planes must be selected. You selected 3.* But in the protein structure there is only one 45th number residue. But I could not understand why it is showing selected 3 repeatedly. Kindly help me. Thanks & Regards Shubhrajyoti Panda Phone: +91-7001855842 Email: panda.jyoti.shubhra@gmail.com