O.B. Tomilin - Ph. D. (Chem.), Head of Department Physical Chemistry, Ogarev Mordovian State University (Saransk). E-mail: tomilinob@mail.ru E.E. Muryumin - Ph. D. (Chem.), Associate Professor, Department Physical Chemistry, Ogarev Mordovian State University (Saransk). E-mail: mur_ee@mail.ru E.V. Rodionova - Research Scientist, Department Physical Chemistry, Ogarev Mordovian State University (Saransk). E-mail: rodionova_i87@mail.ru

The calculations of electron structure of model fragments of side-wall carbon nanotubes (SWCNT) with chirality (n, 0) and (n, n) were carried out at the Hartree-Fock level using a standard 3-21G basis set. Analysis of molecular orbitals (MO) shows that a molecular orbital where electron density is localized at the ends of the SWCNT exists among vacant MOs, providing favorable conditions for field electron emission (emission molecular orbital). Calculated energies of emission molecular orbitals are similar to experimental energy values of electron field emission from SWCNT. It has been shown that the mechanism of field electron emission from SWCNT has a step character namely: excitement of electrons to emission molecular state and electron emission from the cathodic material. The results may serve as a base for interpretation of causes of dispersion in experimentally observed emission energy of electrons in carbon nanotubes (structural changes of the SWCNT as well as the macrostructure of the cathodic material).

 

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