[gmx-users] calculation of distance between the center of geometry of two proteins

[SHAHEE ISLAM]

hi,
to calculate the distance between the center of geometry of two
proteins, i am using this command
g_dist -f md_0_1_noPBC.xtc -s dynamic.tpr -n index.ndx -o distave.xvg
-select 'cog of group "Chain_A" plus cog of group "Chain_B"'
Invalid command line argument:
-select
here in this index file the two chain group name Chain_A and Chain_B
how i will select the two chain.

thanking you
shahee islam
university of calcutta