1. J. M. Hunter, J. L. Fye, and M. F. Jarrold, J. Chem. Phys. 3, 1785 (1993); J. M. Hunter, J. L. Fye, E. J. Roskamp, and M. F. Jarrold, J. Chem. Phys. 98, 1810 (1994).
2. V. A. Schweigert, A. L. Alexandrov, Y. N. Morokov, and V. I. Bedanov, Chem. Phys. Lett. 235, 221 (1995).
3. V. A. Schweigert and A. L. Alexandrov, Chem. Phys. Lett. 263, 551 (1996).
4. G. A. Dyuzhev and V. I. Karataev, Fiz. Tverd. Tela (St. Petersburg) 36, 2795 (1994) [Phys. Solid State 36, 1528 (1994).
5. D. Afanas’ev, I. Blinov, A. Bogdanov et al., Zh. Tekh. Fiz. 64(10), 76 (1994) [Tech. Phys. 39, 1017 (1994)]; D. V. Afanas’ev, A. A. Bogdanov, G. A. Dyuzhev et al., Zh. Tekh. Fiz. 67(2), 125 (1997) [Tech. Phys. 42, 234 (1994)].