密度泛函理论计算Kubas作用：Ti(I) 离子与氢分子之间的吸附能

In this paper, the structures formed by Ti(I) ion and hydrogen molecules were investigated by using different functional theory (DFT) methods with Gaussian 09 package. The successive adsorption energies of Ti ion to hydrogen molecules were calculated and compared with experimental results. The calculations show that the H-H bond length become longer when hydrogen molecule is adsorbed on the Ti ion, which indicates the Kubas interaction. Among all thirteen DFT methods, the TPSS and PBE1PBE methods gave out the most accurate adsorption energies, which agreed well with the experimental results. It was found that zero-point energy correction is very important to obtain the reliable adsorption energyies. The basis set superposition error is negligible in our calculations. The results from the perturbation theory MP2 method deviated from the experimental result distinctly, although the MP2 method was often used to calculate the weak interactions.