[gmx-users] g_sas, what should be "a group for output"

[xieyh at hkusua.hku.hk]

Dear users:

A very simple question, but I can not find any support from the  manual or
mailing list. 
I have a system "protein in water". When I use "g_sas" to calculate the
hydrophobic/hydrophilic area of protein. I am asked to select a calculation
group and a group for output. Of course, the calculation group should be
"Protein". 
But what is "a group for output"? protein or solvent? And what is that meaning?

Thanks a lot.



Xie YH
Hong Kong Univ.