Today, theoretical and computational chemistry can accurately and effectively express the geometry of molecules, reactivity, and electrical properties. In this work, computational chemistry was used to determine aromaticity.

The concept of aromaticity is widely used in chemistry, and with the development of aromatic compounds, the application of Hoeckel's rule for unstable π-electrons, which relates aromaticity to the flatness of compounds, limited it and caused a new definition to be considered for it. Today, aromaticity is the most suitable option for expressing the magnetic properties of compounds. In 1996, the NICS index (nucleus-independent chemical shift quantity) by Schiller and his colleagues to determine the aromaticity and anti-aromaticity of various compounds. Circular and cluster were introduced and now it can be done easily in all kinds of computing software due to its simple understanding and proper performance. The value of NICS is defined as the absolute negativity of electron coverage calculated at the center of the ring or other points, and rings with negative NICS values ​​are considered aromatic and positive values ​​are considered antiaromatic, which is expressed in ppm. [1,2] In this research, using the method and quantum calculations in the initial basis set (HF) and density functional (B3LYP) in different series, it has been used to check the stability, and the NICS index is used to determine The characteristic of aromaticity is used.