Ferroelectric multiple polarization states offer higher information storage density and promising opportunities for neuromorphic computing, making them an important frontier in next-generation ferroelectric research. Reorientable ferroelectrics provide an alternative pathway to realize multiple polarization states. In this work, we report that two-dimensional graphitic carbon nitride ($g\text{−}{\mathrm{C}}_3{\mathrm{N}}_4$) exhibits this reorientable ferroelectric behavior, originating from its distinctive internal structure. First-principles calculations reveal that both $Pca{2}_1$-triazine and $Pca{2}_1$-heptazine $g\text{−}{\mathrm{C}}_3{\mathrm{N}}_4$ exhibit spontaneous polarization with three equivalent ferroelectric states, each separated by 120°. Unlike conventional ferroelectrics, they do not exhibit antiparallel polarization and therefore cannot undergo polarization flipping. Instead, they possess several polarization states oriented along different directions. The piezoelectric coefficients $d_{22}$ of the $Pca{2}_1$-triazine and $Pca{2}_1$-heptazine $g\text{−}{\mathrm{C}}_3{\mathrm{N}}_4$ are 1.33 and 0.97 pm/V. Such novel properties highlight $g\text{−}{\mathrm{C}}_3{\mathrm{N}}_4$ as a promising candidate for future miniaturized and integrated multifunctional electronic devices.

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• Electric polarization
• Ferroelectrics
• Paraelectrics
• Piezoelectrics
• Bloch wave theory
• Density functional theory
• First-principles calculations
• Molecular dynamics