Subscripts for the output of the correlation functions

In the file dynsf_out_old.m that is produced for the molten sodium chloride example, what do the different subscripts for the correlation functions represent? For example, for G(r,t), I see:

G_r_t_0_0
G_r_t_0_1
G_r_t_1_1

I think they refer to the different species, but how is Na+ distinguished from Cl- in this example? It is not clear to me from the index file which one must be 0 and which must be 1.

Yes it refers to the different atom types.
I think it should simply be the same as the order of the index file.

When you run dynasor you should see some information like

INFO: -- With a total of 8640 particles, 3 types.
INFO: -- 1. 1728 Cs
INFO: -- 2. 1728 Pb
INFO: -- 3. 5184 I