Anchoring of Ca metal on g- \(\hbox {C}_3\hbox {N}_4\) presents a promising approach for creating effective catalysts. This study utilized DFT with PBE0-D3BJ/def2-TZVP to explore the interaction between Ca atom and g- \(\hbox {C}_3\hbox {N}_4\) . Theoretical model of g- \(\hbox {C}_3\hbox {N}_4\) was validated with experimental FTIR spectra. When Ca is adsorbed, the g- \(\hbox {C}_3\hbox {N}_4\) structure naturally curves, accompanied by increased \(\pi\) -electron delocalization. The interaction energy suggests that Ca anchoring is thermodynamically advantageous. NBO analysis revealed the significant involvement of d-orbitals of Ca, resulting in spatially directed bonding with inner nitrogen atoms. The reduction in the HOMO–LUMO gap of Ca/g- \(\hbox {C}_3\hbox {N}_4\) compare with g- \(\hbox {C}_3\hbox {N}_4\) indicates the metallic nature. These insights provide a computational framework for the strategic design of Ca/g- \(\hbox {C}_3\hbox {N}_4\) , where curvature and orbital hybridization may improve catalytic efficiency.
