X2H hydrides (X=Al, Si, P, and S) have been investigated using coupled cluster theory with single, double, and triple excitations, the latter incorporated as a perturbative correction [CCSD(T)]. These were performed utilizing a series of correlation-consistent basis sets augmented with diffuse functions (aug-cc-pVXZ, X = D, T, Q). Al2H and Si2H are determined to have H-bridged C2v structures in their ground states: the Al2H ground 2state is of B1 symmetry with an Al-H-Al angle of 87.6, and the Si2H ground state is of 2A1 symmetry with a Si-H-Si angle of 79.8. However, P2H and S2H have non-bridged, 2bent Cs structures: the P2H ground state is of A' symmetry with a P-P-H angle of 97.0, 2and the S2H ground state is of A' symmetry with an S-S-H angle of 93.2. Ground state geometries, vibrational frequencies, and electron affinities have been computed at all levels of theory.