The performance of ab initio methods (MP2, DFT/B3LYP, random-phase approximation (RPA), CCSD(T) and QCISD(T)) in predicting interaction energy of X–H...π (X-H=HCCH, HCl, HF; π=C₂H₂, C₂H₄, C₆H₆) hydrogen complexes are assessed systematically. The CCSD(T)/CBS benchmarks of interaction energy are reported. It is found that RPA agrees well with CCSD(T)/CBS benchmarks and experimental results. CCSD(T) and QCISD(T) perform the best only when compared with CCSD(T)/CBS benchmarks, MP2 performs well only for experimental data. B3LYP provides the worst accuracy. Additionally, the equilibrium structure, interaction type of X-H...π hydrogen complexes are investigated by the natural bond orbital (NBO) and the non-covalent interaction index (NCI).

从头算方法（MP2，DFT / B3LYP，随机相位逼近（RPA），CCSD（T）和QCISD（T））在预测X–H ...π（XH = HCCH，HCl， HF；π= C ₂ H ₂，C ₂ H ₄，C ₆ H ₆氢络合物进行系统评估。报告了相互作用能的CCSD（T）/ CBS基准。发现RPA与CCSD（T）/ CBS基准和实验结果非常吻合。仅当与CCSD（T）/ CBS基准相比，CCSD（T）和QCISD（T）表现最佳，MP2仅对实验数据表现良好。B3LYP提供最差的精度。此外，还通过自然键轨道（NBO）和非共价相互作用指数（NCI）研究了XH ...π氢络合物的平衡结构，相互作用类型。