Since the original Olah‘s discovery a large  number of carbocations have been prepared and their properties studied in great detail. Stable carbocations could be prepared through the use of extremely acidic compounds. Thus, pentacoordinated carbonium ions have been obtained from methane higher alkanes and various cycloalkanes. However, the characterization of these protonated species using spectroscopic techniques is a difficult task to accomplish. This fact reveals the importance of using theoretical tools to complement experimental efforts to study suitably these chemical ions. In this review, we present an exhaustive study on structural investigations and topologic characterizations using atoms-in-molecules method of carbonium ions (C=1-4) in order to get a suitable improvement of our understanding of the chemical bonding in these species.