The interactions between kinds of corrosion inhibitors, benzotriazole (BTA), methyl benzotriazole-5-carboxylate (MBTC), butyl benzotriazole-5-carboxylate (BBTC), hexyl benzotriazole-5-carboxylate (HBTC), octyl benzotriazole-5-carboxylate (OBTC) and Cu₂O crystal have been simulated by molecular dynamics (MD). The results showed that the binding energies of corrosion inhibitors with Cu₂O crystal in neutral medium were bigger than those in acidic medium, but the orders of binding energy were both as follows: OBTC＞HBTC＞BBTC＞MBTC＞BTA. The analysis of various interactions and pair correlation functions of all systems indicated that binding energies were mainly determined by coulomb interaction, and coordination bonds were formed between the copper atoms in Cu₂O crystal and the nitrogen atoms in corrosion inhibitors. Benzotriazole and its derivatives were deformed during their combining with the (001) face of Cu₂O crystal, but all the deformation energies were far less than respective nonbond interaction energies.

Key words: molecular dynamics, benzotriazole and its derivative, cuprous oxide, corrosion inhibitor, binding energy, pair correlation function, deformation energy