Abstract: We proposed a periodic interaction model for the layered double hydroxides, CuxZn3-xAl-LDHs. Based on density functional theory, the geometry of CuxZn3-xAl-LDHs was optimized using the CASTEP program. Jahn–Teller effect and the stability was investigated by analyzing the geometric parameters, hydrogen-bonding, charge populations, and binding energies. Results showed that the structure of staggered arrangement of Cu2+ and Zn2 + in the layer was relatively stable. As the amount of Cu2+ substituted Zn2 + in the layer increased, the symmetry of unit cell became weaker, and Jahn–Teller effect of the copper had little effect on the central Al3 +. The strength of electrovalent bond became stronger while the strength of covalent bond became weaker with the increase of Cu2+ substituted Zn2 + in the layer, so the covalent crystal of CuxZn3-xAl-LDHs transited to the ionic crystal gradually. The distortion caused by Jahn–Teller effect made an enhanced supermolecular interaction between the host layer and the guest, the strength of electrostatic interactions became weaker while the strength of hydrogen-bonding became stronger, and hydrogen-bonding was superior to the electrostatic interaction. In general, the absolute value of he binding energy decreased gradually with an increase in the number of Cu2+, then the chemical stability of the system got worse, and it was significant for synthesis of Cu-LDHs.

Key words: Layered double hydroxides, Distortion angle, Jahn–Teller effect, Binding energy, Density functional theory