It is found that in certain cases the X-H bonds of the X delta+-H delta- polarity may weakly interact with lone pair vacancies in Y (superset of Y), leading to weak X delta+-H delta- ... superset of Y structures. These structures, which are referred to as charge-inverted hydrogen bonds (CIHB), were computationally established for several pairs of X delta+-H delta- donors and hydrides of the 13th group of the periodic table and shown to feature the characteristics of the usual hydrogen bonds. (C) 2009 Elsevier B. V. All rights reserved.