Structure and dissociation energy of weakly bound H 2n+1+ (n = 5−8) complexes

• Published in: International journal of quantum chemistry 2007, Vol.107 (4), p.988-997
• Main Authors: Seo, Hyun-Il, Sun, Ju-Yong, Shin, Chang-Ho, Kim, Seung-Joon
• Format: Article
• Language: English
• Subjects: ab initio; dissociation energies; hydrogen clusters; TZ2P CCSD(T)
• ISSN: 0020-7608; 1097-461X
• DOI: 10.1002/qua.21212

The geometrical parameters, vibrational frequencies, and dissociation energies for H 2n+1+ (n = 5–8) clusters have been investigated using high level ab initio quantum mechanical techniques with large basis sets. The highest level of theory employed in this study is TZ2P CCSD(T). The C1 structure of H 15+ is predicted to be a global minimum, while the Cs structure of H 15+ is calculated to be a transition state. Harmonic vibrational frequencies are also determined at the DZP and TZ2P CCSD levels of theory. The dissociation energies, De, for H 2n+1+ (n = 5–8) have been predicted using energy differences at each optimized geometry, and zero‐point vibrational energies (ZPVEs) are considered to compare with experimental values. The dissociation energies (Do) have been predicted to be 1.69, 1.65, 1.65, and 1.46 kcal · mol for H 11+, H 13+, H 15+ (C1 symmetry) and H 17+, respectively, at the TZ2P CCSD(T) level of theory. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007