Because the traditional storage of methane in the condensed state in high-pressure vessels is rather dangerous, and to store a large amount of gas using adsorbents is impossible at normal ambient conditions, we have developed a nanocapsule, which combines the advantages of a high-pressure vessel and adsorbents--a large methane mass content and safe-keeping. A nanocapsule is a system of combined nanotubes forming bottle-like pores, the entrance to which is closed by a positively charged endohedral complex (K@C60) with the help of an electric field. In normal ambient conditions, the nanocapsule can retain the amount of methane adsorbed under charging conditions. The processes taking place during the storage of methane and the methane desorption from the nanocapsule are analysed and the value of the electric field intensity necessary for the transfer of the K@C60 in the nanocapsule is determined. The nanocapsule discussed can retain approximately 17.5 mass% of methane at an internal pressure of 10 MPa and a temperature of 300 K.

Spontaneous explosive crystallization in a selenium/copper bilayer nanofilm has been experimentally studied. It has been shown that the formation of a microcrack network in the selenium film is a decisive factor for spontaneous explosive crystallization. The microcrack network is an efficient channel for the relaxation of the collected energy of elastic stresses in the selenium film. The relaxation of this energy accelerates crystallization and transfers it to the explosive regime. It has been found that crystalline phases appearing in the products of the reaction after spontaneous explosive crystallization depend on the ratio of the thicknesses of the copper and selenium films.

A nanocapsule for safe and effective methane storage is investigated by the method of molecular dynamics. The mass content of methane in the nanocapsule reaches the value of 14.5 mass%. The nanocapsule consists of two parts: a locking chamber and a storage area. The locking chamber is the nanotube (10.10), open at one end, with a K@C₆₀ ¹⁺endohedral complex inside it. The storage area is a nanotube (20.20). The locking chamber and the storage area are joined with each other and form T-junction. The locking chamber is opened at the methane filling and the discharge stages, and it is closed at the storage stage. Thanks to the locking chamber, methane molecules are stored in the nanocapsules under normal external conditions. Opening and closing of the locking chamber are carried out by the K@C₆₀ ¹⁺endohedral complex displacement, which is done by the electric field action. The specific structure of the nanocapsule allows two aims to be reached: a high methane mass content and significant level of safety.

The paper presents an analytical review of theoretical methods for modeling functional nanostructures. The main evolutionary changes in the approaches of quantum-mechanical modeling are described. The foundations of the first-principal theory are considered, including the stationery and time-dependent Schrödinger equations, wave functions, the form of writing energy operators, and the principles of solving equations. The idea and specifics of describing the motion and interaction of nuclei and electrons in the framework of the theory of the electron density functional are presented. Common approximations and approaches in the methods of quantum mechanics are presented, including the Born–Oppenheimer approximation, the Hartree–Fock approximation, the Thomas–Fermi theory, the Hohenberg–Kohn theorems, and the Kohn–Sham formalism. Various options for describing the exchange–correlation energy in the theory of the electron density functional are considered, such as the local density approximation, generalized and meta-generalized gradient approximations, and hybridization of the generalized gradient method. The development of methods of quantum mechanics to quantum molecular dynamics or the dynamics of Car–Parrinello is shown. The basic idea of combining classical molecular modeling with calculations of the electronic structure, which is reflected in the potentials of the embedded atom, is described.