Initial structural relaxation of the 2D biphenylene network unit cell has been carried out with AMS-BAND version 2022, 57,58 using the exchange-correlation functional by Perdew, Burke, and Ernzerhof (PBE), the semiempirical DFT-D3(BJ) dispersion correction and 2D periodic boundary conditions. It uses Slater-type orbitals (STOs), and a "Becke 3" grid is set for integration. Additionally, a TZ2P basis set and a regular (55) Monkhorst Pack k-mesh is chosen, scalar relativistic effects are captured via the ZORA approximation, and the electron density has been converged to 1×10 -6 𝑒 -√𝑁 atoms . Forces have been converged to 3×10 -2 eV Å -1 , SCF energy to 3×10 -4 eV and the stress-energy per atom to 1×10 -2 eV Å -2 per atom. All further structural optimizations and the adsorption energies (Eads) have been carried out using the Vienna ab initio simulation package (VASP) version 5.4.4 using PBE-D3(BJ) and 3D periodic boundary conditions. VASP uses the projector augmented wave (PAW) formalism, for which a kinetic energy cutoff of 400 eV is chosen. A Γ(331)-centred Monkhorst-Pack grid is chosen for sampling reciprocal space and convergence criteria of 10 -6 eV and 10 -2 eV Å -1 for energies and forces, respectively. The transition states have been optimized using climbing image nudged elastic band (CI-NEB) calculations after using either an image-dependent pair potential (IDPP) or the geodesic interpolation. The VaspBandUnfolding code was used to create the paths in reciprocal space and calculate effective band structures. For the partial charge analysis, Hirshfeld-I charges are used, and for the aromaticity investigations, the harmonic oscillator model of aromaticity (HOMA) since it is easily applicable to periodic systems. For the investigation of the multiradical character, the system's magnetization has been initialized according to the results of Alcon et al. using PBE0.