[gmx-users] Question regarding g_order

[sa]

Hi all,
I am trying to compute the order parameters for the sn1 and sn2 chains of
DOPC (CHARMM36)  in bilayer . I am using the g_order tool (v4.6.3).
I have constructed for  each DOPC chain two index files that contains in
the first one all the Carbon atoms where the first Carbon is C=O and the
last one is the last methyl. The second index file for the unsat
calculations contains only the carbons of the C-C9=C10-C.

I am confused here, since the file obtained from g_order w/o the -unsat
argument contains only 16 values and in case of the file generated with
g_order w the -unsat argument 2 values. I am aware that I need to replace
the 9 -10 values in first by those of the second file. However I would like
to compare my SCD values with those obtained by Jämbeck and P. Lyubartsev
(figure 2 in ref [1] ), The authors present graph for DOPC with 17 values.
How it is possible? Did I miss something, here?

-- g_order w/o unsat
# g_order_mpi is part of G R O M A C S:
#
# GROup of MAchos and Cynical Suckers
#
@    title "Deuterium order parameters"
@    xaxis  label "Atom"
@    yaxis  label "Scd"
@TYPE xy
           1        0.20508
           2       0.148241
           3       0.184247
           4       0.184565
           5       0.184457
           6       0.166101
           7       0.118359
           8      0.0774722
           9      0.0703466
          10      0.0511651
          11      0.0977673
          12      0.0968413
          13       0.100903
          14      0.0869513
          15      0.0806322
          16      0.0602708

-- g_order w/ unsat
# g_order_mpi is part of G R O M A C S:
#
# GRoups of Organic Molecules in ACtion for Science
#
@    title "Deuterium order parameters"
@    xaxis  label "Atom"
@    yaxis  label "Scd"
@TYPE xy
           1       0.104554
           2      0.0111027

[1] http://pubs.acs.org/doi/full/10.1021/ct300342n

Thank in advance