[gmx-users] g_sas and f_index

[Mark Abraham]

Hi,

g_sas for determining solvent accessible area requires a .tpr file as 
input, presumably to extract the charges in order to determine whether 
atoms are hydrophobic or hydrophilic. However the -f_index option allows 
a .ndx file to make this assignment. Thus it seems to me that these 
options should be mutually exclusive (if there's no other function of 
the .tpr file), or at least the .tpr should be optional if -f_index is used.

Am I missing something here?

Mark