Accurate ab initio calculations on the potential energy surfaces (PESs) of the lowest electronic states of the neutral HSS and those of the electronic states of the HSS- negative ion correlating to the bound asymptotes of this molecular system, reveal that the ground state of HSS- (i.e. 1A') and the long range parts of the anionic PESs are stable against the autodetachment processes. In light of these calculations, the [HS + S]- and [S2 + H]- reactive systems are examinated and found forming the HSS-( 1A') ions either directly or after spin-orbit and / or vibronic and / or Renner-Teller couplings, in competition with fast electron loss processes. The three-dimensional PES of the unique bound electronic state of HSS- (i.e. 1A') is generated using the coupled cluster approach and a large basis set. A set of spectroscopic parameters for HSS-/DSS- ( 1A') and their rovibrational spectra up to 3700 cm-1 are deduced from our 3D PES.