The properties of liquids of pentane, hexane, cyclohexane and cyclopentane were observed at 300 K. Alkanes were observed in the "united atoms" model and before the simulation were classified into point groups by group theory tools. For each of the alkanes, a reducible representation and theoretically assumed vibrational spectrum, infrared and Raman activity were determined according to the classification. The second part of the paper deals with simulations of the molecular dynamics of the mentioned alkanes in the OPLS and TraPPE force field. Thermodynamic properties (vapor enthalpy, density, isothermal compressibility and specific heat capacity), structure (radial distribution function) were observed, and special emphasis was placed on dynamic quantities. The results of group theory were taken as an aid in the classification of vibrational spectrum modes. Finally, the rotational correlation function and the corresponding relaxation time were determined for each alkane. The obtained results resulted in a scientific paper: Ivan Koljanin, Martina Požar, Bernarda Lovrinčević: Structure and dynamics of liquid linear and cyclic alkanes: a molecular dynamics study, sent for review to the journal Fluid Phase Equilibria in June 2021.