1. V. Kveder, M. Kittler, and W. Schroeter, Phys. Rev. B 63, 115208 (2001).
2. A. Umerski and R. Jones, Philos. Mag. A 67, 905 (1993).
3. M. I. Heggie, S. Jenkins, C. P. Ewels, et al., J. Phys.: Condens. Matter 12, 10263 (2000).
4. A. L. Buchachenko, R. Z. Sagdeev, and K. M. Salikhov, Magnetic and Spin Effects in Chemical Reactions (Nauka, Novosibirsk, 1978), p. 296.
5. V. I. Al’shits, E. V. Darinskaya, T. M. Perekalina, and A. A. Urusovskaya, Fiz. Tverd. Tela (Leningrad) 29, 467 (1987) [Sov. Phys. Solid State 29, 265 (1987)].