On the stability and lifetime of GaO2+ in the gas phase
- 81 Downloads
- 7 Citations
Abstract
The electronic structure, stability, and lifetime of GaO2+ have been investigated using high-level ab initio calculations. The potential energy curves have been calculated at the CCSD(T)/aug-cc-pV5Z and at the MS-CASPT2/ANO-RCC levels of theory. Lifetimes were evaluated using the Exterior Complex Scaling (ECS) method and B-spline basis functions. Our calculations show that GaO2+ is a metastable species in the gas phase, since the diatomic dication, in its ground state, lies 97.1 kcal/mol above the Ga+ (1S) + O+ (4S) dissociation limit. However, the energy barrier that has to be overcome to reach this limit is 3 kcal/mol high so that five vibrational resonances can be accommodated between the bottom of the well and the top of the barrier. The evaluated lifetimes vary from hundreds of femtoseconds to approximately 1 s, so at least two of them have long enough lifetimes (1 s and 91 μs) to be detected using mass spectrometry techniques, in agreement with the experimental evidence. In the experiment (Fiser et al. in Eur J Mass Spectrom 15:315–324, 2009), GaO2+ was observed for an ion flight time of about ~12 μs through a magnetic-sector mass spectrometer and unambiguously identified by its isotopic abundance. Our results also show that isotopic effects on the resonances’ energies and on their lifetimes, when 70Ga is replaced by 69Ga or 71Ga, are very small (~0.1 and ~1%, respectively), reflecting the large mass of the system.
Keywords
Doubly charged species Lifetimes Ab initio calculations Coulomb explosion GaO Gas phaseNotes
Acknowledgments
We thank Klaus Franzreb for sending us his experimental results (ref.16) and his suggestion to calculate GaO2+. This work has been partially supported by the DGI Project No. CTQ2009-13129-C01, by the Project MADRISOLAR2, Ref.: S2009PPQ/1533 of the Comunidad Autónoma de Madrid, by Consolider on Molecular Nanoscience CSC2007-00010, and by the COST Action CM0702. IC and AP gratefully acknowledge a Juan de la Cierva post-doctoral contract from the Ministerio de Ciencia e Innovación of Spain. A generous allocation of computing time at the CCC of the UAM is also acknowledged.
References
- 1.Bain O, Giguere PA (1955) Can J Chem 33:527–545CrossRefGoogle Scholar
- 2.Pople JA, Raghavachari K, Frisch MJ, Binkley JS, Schleyer PV (1983) J Am Chem Soc 105:6389–6398CrossRefGoogle Scholar
- 3.Huang HH, Xie YM, Schaefer HF (1996) J Phys Chem 100:6076–6080CrossRefGoogle Scholar
- 4.Schroder D, Schalley CA, Goldberg N, Hrusak J, Schwarz H (1996) Chem Eur J 2:1235–1242CrossRefGoogle Scholar
- 5.Pyykkö P (1995) J Am Chem Soc 117:2067–2070CrossRefGoogle Scholar
- 6.Schroder D, Schwarz H, Hrusak J, Pyykkö P (1998) Inorg Chem 37:624–632CrossRefGoogle Scholar
- 7.Pyykkö P (1989) Chem Phys Lett 162:349–354CrossRefGoogle Scholar
- 8.El-Nahas AM (2000) Chem Phys Lett 329:176–178CrossRefGoogle Scholar
- 9.Stace AJ, Walker NR, Wright RR, Firth S (2000) Chem Phys Lett 329:173–175CrossRefGoogle Scholar
- 10.Schroder D, Schwarz H, Wu JL, Wesdemiotis C (2001) Chem Phys Lett 343:258–264CrossRefGoogle Scholar
- 11.Palacios A, Corral I, Mó O, Martín F, Yáñez M (2005) J Chem Phys 123:014315 (014311-014315)Google Scholar
- 12.Palacios A, Martín F, Mó O, Yáñez M, Maksic ZB (2004) Phys Rev Lett 92:133001CrossRefGoogle Scholar
- 13.Schroder D, Schwarz H (1999) J Phys Chem A 103:7385–7394CrossRefGoogle Scholar
- 14.Franzreb K, Hrusak J, Alikhani ME, Lorincik J, Sobers RC, Williams P (2004) J Chem Phys 121:12293–12302CrossRefGoogle Scholar
- 15.Franzreb K, Sobers RC, Lorincik J, Williams P (2004) J Chem Phys 120:7983–7986CrossRefGoogle Scholar
- 16.Fiser J, Franzreb K, Lorincik J, Williams P (2009) Eur J Mass Spectrom 15:315–324CrossRefGoogle Scholar
- 17.Ohno Y, Kuroda T, Nakamura S (1978) Surf Sci 75:689–702CrossRefGoogle Scholar
- 18.Cársky P, Paldus J, Pittner J (2010) Recent progress in coupled cluster methods. Theory and applications. Springer, DordrechtGoogle Scholar
- 19.Helgaker T, Jorgensen P, Olsen P (2000) Molecular electronic-structure theory. Wiley, ChichesterGoogle Scholar
- 20.Dunning TH Jr (1989) J Chem Phys 90:1007CrossRefGoogle Scholar
- 21.Wilson AK, Woon DE, Peterson KA, Dunning TH Jr (1999) J Chem Phys 110:7667CrossRefGoogle Scholar
- 22.Roos BO (1987) In: Lawley KP (ed) Advances in Chemical Physics: Ab initio methods in quantum chem, Part II. Wiley, New YorkGoogle Scholar
- 23.Finley J, Malmqvist P-A, Roos BO, Serrano-Andrés L (1998) Chem Phys Lett 288:299CrossRefGoogle Scholar
- 24.Roos BO, Lindh R, Malmqvist P-A, Veryazov V, Widmark P-O (2005) J Phys Chem A 108:2851CrossRefGoogle Scholar
- 25.Karlström G (2003) Comput Mater Sci 28:222CrossRefGoogle Scholar
- 26.Frisch MJ (2004) GAUSSIAN 03, revision C.02. Gaussian, Inc., WallingfordGoogle Scholar
- 27.McCurdy CW, Rescigno TN (1997) Phys Rev A 56:R4369CrossRefGoogle Scholar
- 28.McCurdy CW, Rescigno TN, Byrum D (1997) Phys Rev A 56:1958CrossRefGoogle Scholar
- 29.McCurdy CW, Martín F (2004) J Phys B 37:917CrossRefGoogle Scholar
- 30.DeYonker NJ, Peterson KA, Wilson AK (2007) J Phys Chem A 111:11383–11393CrossRefGoogle Scholar