Hi all,
I have a question about the positive value of the output of the ellipticity 222 Θ_222 , as an output from the gmx helix package.
Specifically, I run
“gmx helix -s top.tpr -n index.ndx -f traj.xtc -b 400000 -cz conf.gro”
and got the “cd222.xvg” file like this:
"# gmx helix is part of G R O M A C S:
Great Red Oystrich Makes All Chemists Sane
@ title “Ellipticity at 222 nm”
@ xaxis label “Time (ps)”
@ yaxis label “nm”
@TYPE xy
400000 59.57
400050 60.32
400100 57.64
400150 59.94
400200 60.63
400250 56.91
400300 56.67…".
Why is the output value of the ellipticity positive, instead of being negative? Since according to Hirst and Brooks (1994) (DOI: 10.1006/jmbi.1994.1644), the ellipticity is negative (Table 2/ page 176).
May someone have any explanation, please?
Many thanks,
Anh Mai