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The article discusses a promising method for producing carbon quantum dots (C-dots) from coal. Coal grades A (anthracite), K (coking), OS (lean-sintered) were used as raw materials. The separated particles were investigated by X-ray diffraction and optical methods of analysis. The interplanar distances in C-dots and the phase ratio in the samples are determined. The intrinsic absorption region was determined from the optical spectra and the band gap of the obtained C-dots was estimated. Lines of photoluminescence were found in the UV and visible ranges.

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A study of the crystal structure, mechanical and acoustic properties of two [Formula: see text] and [Formula: see text] monoclinic phases of naphthalene and anthracene was performed using ab initio method of linear combination of atomic orbitals (LCAO) and basis sets: C_6-21G*, H_3-1p1G. The method was implemented in the CRYSTAL[Formula: see text]14,[Formula: see text]17 software package using electron density functional theory including van der Waals interactions (DFT-D2 and DFT-D3 (BJ)), in the local density approximation (LDA) with VWN exchange-correlation potential, gradient approximation PBE exchange-correlation functional and B3LYP hybrid functional. The calculated elastic constants for the first time are in moderate agreement with experimental data. Bulk modulus [Formula: see text], shear modulus [Formula: see text], Young’s modulus [Formula: see text] and the Poisson’s ratio [Formula: see text], as well as acoustic properties (average velocity of sound [Formula: see text], the Debye temperature [Formula: see text], and acoustic Grüneisen parameter [Formula: see text]) were obtained using the Voigt–Reuss–Hill model.