EN
We present a comprehensive study of magnetic properties of Cr_8F_8(Piv)_{16} molecular ring (in short Cr8) using the package SIESTA with several choices of chromium pseudopotential parameters. We use generalized gradient approximation to investigate properties of Cr8 ring approximated by replacing the pivallic group by H atoms (hydrogen saturation). For different choice of chromium pseudopotential we examine the electronic and magnetic properties of Cr8 molecule. We compare highest occupied molecular orbital and the lowest unoccupied molecular orbital gaps for both spin channels, magnetic moments, and exchange interaction parameter J. The influence of pseudopotential parameters on obtained results is discussed. Finally our results are compared with other theoretical approaches and experimental data.