Ne-HF分子间势的从头计算研究(英文)

AN AB INITIO STUDY OF INERMOLECULAR POENTIAL FOR THE NE-HF COMPLES

在用非迭代的三重激发项来校正CCSD的CCSD(T)的理论水平下,采用aug cc pVQZ基函数对Ne NF的分子间势进行了系统的研究。结果表明:Ne-HF以线型结构存在。在极限基的情况下,复合物线型极小点结构Ne H F势阱深为80 77cm-1对应Ne原子到HF分子质心的距离R为0 320nm。相对于第一极小点,在R=0 309nm,Θ=180°处(势阱深为54 443cm-1)有一个第二极小点存在。最后讨论了不同的基函数和理论方法在研究此类弱束缚态复合物的分子间势时的可靠性及其对结果的影响。

The potential energy surface of the ground state of the NeHF complex has been calculated at several levels of theory, including the single and double excitation coupledcluster method with noniterative perturbation treatment of triple excitation CCSD(T). Calculations have been performed using the augmented correlationconsistent polarzed quadruple zeta basis set (augccpVQZ). The global minimum with a well depth of approximate 80770cm-1 has been found for the linear NeHF structure (Θ=00°) with the distance between the Ne atom and the center of mass of the HF molecule equals 32*!. In addition to the global minimum, there is a secondary minimum at R=30989*! and Θ=180°(a well depth of 54443cm-1). At last, we discuss the effects of the basis sets and theoretical methods on the intermolecular potential calculations of such weakly bound van der Wassls complexes.