Structure and bonding in (R2SiX)2 molecules (X = O, NH, CH2, or S; R = H)

Analysis of the structure and bonding in (R2SiX)2 molecules (X = O, NH, CH2, or S; R = H) by empirical, MNDO, and ab initio molecular orbital methods shows that: (a) the electronic structures of these systems are qualitatively similar, (b) short non- bonded 1,3-Si–Si distances are predominantly determined by the Si–X distance, and (c) the small antibonding Si–Si interactions increase with increasing Si–Si distance.