<p>The molecular geometries of boraphosphabenzene (BP-benzene) and boron phosphorus coronene (BP-coronene) can be misinterpreted when they are obtained from density functional theory (DFT) calculations. In this study, we found that some exchange-correlation (XC) functionals yielded a distorted geometry of the above molecules when P atoms are present in their resonance structures. This phosphorus pyramidalization may be due to spurious errors caused by using these functionals. To verify this behavior, the electronic structures of BP-benzene and BP-coronene were studied using sixteen functionals (B3LYP, B97D, BHLYP, BP96, PBE, PBE0, PWLDA, Slater-Dirac-exchange, TPSS, M05, M06, M062X, M08HX, M11, wB97 and wB97X-D) with the SVP or TZVPP basis sets. The calculations were carried out using the TURBOMOLE and GAMESS programs. The geometry optimization calculations were carried out for each functional using both of the basis sets. Two different initial geometries, plane (D_3h symmetry) and distorted (C1 symmetry) were considered. The optimized geometries of the BP-systems obtained at the MP2/TZVPP and CC2/TZVPP levels of theory exhibited D_3h symmetry. These calculations were used as a reference and compared with those obtained from DFT. The optimized geometries obtained from DFT were found to exhibit C₁ symmetry for the majority of the XC functionals.</p>