Parity alternation of linear ground-state hydrogenated cationic carbon clusters HCnSi+ (n=1-10)

Abstract Making use of molecular graphics software, we have designed numerous models of HC n Si + ( n  = 1–10), and by means of the B3LYP density functional method, performed geometry optimization and calculation on vibrational frequency. The ground-state isomers of HC n Si + ( n  = 1–10) are found to be linear with the Si and H atom located at the ends of the C n chain. When n is even, the C n chain is polyacetylene-like whereas when n is odd, the C n chain displays a structure that fades into a cumulenic-like arrangement towards the Si end. According to the results of mass spectrometric investigation available in the literature, the intensities of even- n HC n Si + are more intense than those of odd- n HC n Si + , implying that the former are more stable than the latter. We detect trends of odd/even alternation in electronic configuration, the highest vibrational frequency, ionization potential, incremental binding energy as well as in certain bond length and certain atomic charge of the linear ground-state structures of the HC n Si + ( n  = 1–10) clusters. The calculation results reveal that the even- n cationic clusters are more stable than the odd- n ones.