采用密度泛函理论方法对氢气吸附进行了基准研究.探讨了不同泛函方法,范德华作用及基组大小在计算中对预测氢气吸附能的影响.研究结果表明,不同泛函预测吸附能给出的偏差很大,范德华作用校正不容忽视;基组和模型尺寸影响相对较小;模型越大对基组依赖性越小;选择小的模型可以通过选择较大基组弥补计算的误差.
A benchmark study of density functional theory( DFT) method was conducted on the adsorption energy of hydrogen. The effects of DFT methods,dispersion and the size of basis sets were explored on the prediction of adsorption energy. The results show that the adsorption energies predicted by different DFT methods varies considerably; the dispersion term can not be ignored; the basis set and model have minor contributions for the final energy refinement; larger models are more independent on the size of basis set,and larger basis set can make up the deficiency of smaller model. The method selection strategy will provide valuable clues for relevant studies.