[gmx-users] double bonds

[Aina Quintilla]

hello, 

i am not a user of gromacs yet.. i would like to use it to simulate the 
behaviour of micelles of SDS soap molecules and molecules themselves in 
water,  and later study the behaviour of the micelles that are formed when 
carbon nanotubes are in such a solution (water+SDS).
i want first to generate the topology file corresponding to SDS and i have a 
question concerning the bonds definition:
is there a way to define whether a bond is simple, double .. ?
and if not , is it necessary? 

thank you