Quantum Monte Carlo and high-level ab initio molecular orbital investigation of dissociation channels of the positronic alkali-metal hydrides, [XH;e+] (X = Li, Na, and K)

  • Yurika Yamada
  • Yukiumi Kita
  • Masanori Tachikawa
  • Mike D. Towler
  • Richard J. Needs
Regular Article
Part of the following topical collections:
  1. Topical issue: Electron and Positron Induced Processes

Abstract

Energy thresholds for dissociation channels of positronic alkali-metal hydrides, [XH;e+] (X = Li, Na, and K), to XH + e+(positron dissociation), XH+ + Ps (positronium dissociation), and X+ + [H;e+] (positronic hydride ion dissociation) have been calculated using quantum Monte Carlo and high-level ab initio molecular orbital methods, and including quantum zero-point vibrational energy of all of the particles. As the atomic number of X increases from Li to K, the dissociation energy to XH + e+ increases because the dipole moment of XH increases with the atomic number of X, while the dissociation energy to XH+ + Ps decreases. The energy threshold for the ionic dissociation to X+ + [H;e+] is also reduced, and we obtain 0.975 (3) eV, 0.573 (12) eV, and 0.472 (19) eV for [LiH;e+], [NaH;e+], and [KH;e+], respectively, for this channel. Our results strongly support the conclusion that, among these three channels, the lowest energy dissociation for [XH;e+] is the pathway to X+ + [H;e+], where X = Li, Na, and K.

References

  1. 1.
    G.F. Gribakin, J.A. Young, C.M. Surko, Rev. Mod. Phys. 82, 2557 (2010) ADSCrossRefGoogle Scholar
  2. 2.
    J.A. Young, C.M. Surko, Phys. Rev. A 78, 032702 (2008) ADSCrossRefGoogle Scholar
  3. 3.
    J.R. Danielson, A.C.L. Jones, J.J. Gosselin, M.R. Natisin, C.M. Surko, Phys. Rev. A 85, 022709 (2012) ADSCrossRefGoogle Scholar
  4. 4.
    M. Tachikawa, H. Sainowo, K. Iguchi, K. Suzuki, J. Chem. Phys. 101, 5925 (1994) ADSCrossRefGoogle Scholar
  5. 5.
    M. Tachikawa, Chem. Phys. Lett. 350, 269 (2001) ADSCrossRefGoogle Scholar
  6. 6.
    J. Mitroy, Phys. Rev. A 73, 054502 (2006) ADSCrossRefGoogle Scholar
  7. 7.
    K. Strasburger, J. Chem. Phys. 114, 615 (2001) ADSCrossRefGoogle Scholar
  8. 8.
    R.J. Needs, M.D. Towler, N.D. Drummond, P. López Ríos, J. Phys.: Condens. Matter 22, 023201 (2010) ADSGoogle Scholar
  9. 9.
    P.J. Reynolds, D.M. Ceperley, B.J. Alder, W.A. Lester Jr., J. Chem. Phys. 77, 5593 (1982) ADSCrossRefGoogle Scholar
  10. 10.
    W.M.C. Foulkes, L. Mitas, R.J. Needs, G. Rajagopal, Rev. Mod. Phys. 73, 33 (2001) ADSCrossRefGoogle Scholar
  11. 11.
    Y. Kita, R. Maezono, M. Tachikawa, M.D. Towler, R.J. Needs, J. Chem. Phys. 135, 054108 (2011) ADSCrossRefGoogle Scholar
  12. 12.
    O.H. Crawford, Proc. Phys. Soc. 91, 279 (1967) ADSCrossRefGoogle Scholar
  13. 13.
    K. Strasburger, Struct. Chem. 15, 415 (2004) CrossRefGoogle Scholar
  14. 14.
    M. Tachikawa, Y. Kita, R.J. Buenker, New J. Phys. 14, 035004 (2012) ADSCrossRefGoogle Scholar
  15. 15.
    M. Tachikawa, R.J. Buenker, M. Kimura, J. Chem. Phys. 119, 5005 (2003) ADSCrossRefGoogle Scholar
  16. 16.
    H. Chojnacki, K. Strasburger, Mol. Phys. 104, 2273 (2006) ADSCrossRefGoogle Scholar
  17. 17.
    Y. Kita, R. Maezono, M. Tachikawa, M.D. Towler, R.J. Needs, J. Chem. Phys. 131, 134310 (2009) ADSCrossRefGoogle Scholar
  18. 18.
    M. Tachikawa, Y. Kita, R.J. Buenker, Phys. Chem. Chem. Phys. 13, 2701 (2011) CrossRefGoogle Scholar
  19. 19.
    F.A. Gianturco, J. Franz, R.J. Buenker, H.-P. Liebermann, L. Pichl, J.-M. Rost, M. Tachikawa, M. Kimura, Phys. Rev. A 73, 022705 (2006) ADSCrossRefGoogle Scholar
  20. 20.
    CRC Handbook of Chemistry and Physics, edited by W.M. Haynes, 94th edn. (CRC Press/Taylor and Francis, Boca Raton, 2013-2014) Google Scholar
  21. 21.
    P. Maldonado, A. Sarsa, E. Buendía, F.J. Gálvez, J. Chem. Phys. 133, 064102 (2010) ADSCrossRefGoogle Scholar
  22. 22.
    N.D. Drummond, M.D. Towler, R.J. Needs, Phys. Rev. B 70, 235119 (2004) ADSCrossRefGoogle Scholar
  23. 23.
    N.D. Drummond, R.J. Needs, Phys. Rev. B 72, 085124 (2005) ADSCrossRefGoogle Scholar
  24. 24.
    H. Nakashima, H. Nakatsuji, J. Chem. Phys. 127, 224104 (2007) ADSCrossRefGoogle Scholar
  25. 25.
    R.J. Buenker, H.-P. Liebermann, V. Melnikov, M. Tachikawa, L. Pichl, M. Kimura, J. Phys. Chem. A 109, 5956 (2005) CrossRefGoogle Scholar
  26. 26.
    J. Mitroy, G.G. Ryzhikh, J. Phys. B 33, 3495 (2000) ADSCrossRefGoogle Scholar
  27. 27.
    M. Mella, G. Morosi, D. Bressanini, S. Elli, J. Chem. Phys. 113, 6154 (2000) ADSCrossRefGoogle Scholar

Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Yurika Yamada
    • 1
  • Yukiumi Kita
    • 1
  • Masanori Tachikawa
    • 1
  • Mike D. Towler
    • 2
  • Richard J. Needs
    • 2
  1. 1.Quantum Chemistry Division, Yokohama City UniversityYokohamaJapan
  2. 2.TCM Group, Cavendish Laboratory, University of CambridgeCambridgeUK

Personalised recommendations