[1] Instituto de Química, UNAM, Coyoacán, 04510 Mexico D.F., Mexico
[2] Dept. Modelling Phys.-Chem. P., Faculty of Chemistry, MCS University, 20031 Lublin, Poland
[3] Inst. for Condensed Matter Physics, Natl. Acad. of Sci. of the Ukraine, 290011 Lviv, Ukraine