Theoretical And Experimental Study Of Ammonia Clusters (the Nh <sub> 3 </ Sub>) <sub> N </ Sub> (n = 2 ~ 8)

With the development of industry and society, the problem of pollution becomes more and more serious, and it adds many challenges to people's lives and health. Ammonia as one of many pollutants is an alkalescent matter. It has strong thrill smell, and it can do great damage to people's body. In recent years, many researches have been done on it.In this paper, we mainly make our discussion as follows.In chapter 1, we firstly introduce the meaning and methods of research on ammonia clusters. Then, the research actuality of the subject is listed.In chapter 2, we firstly introduce the theory computation method used in this paper and the development process of density functional theory. At the end of this chapter, we introduce some widely used simulation packages, in which we pay more attention to the Gaussian software and the Gaussian basis set.In chapter 3, we introduce the techniques of supersonic molecular beam and laser mass spectrum.In chapter 4, we study the peculiarity and stability of ammonia clusters (NH₃)_n (n=2～8), using the method of density functional theory with computation procedure of Gaussian 03W. The growth rule of ammonia clusters are found out. Then, the IR harmonic vibration spectra of the most stable structures of ammonia clusters (NH₃)_n (n=2～8) of each cluster size is discussed. In addition, isomerization of the two isomers of (NH₃)₂ is studied, and the forward and back reaction activation energies are gained.In chapter 5, the laser-ionization progress of ammonia clusters is studied at the laser wavelength of 355nm. The result shows that there are ionic series of ammonia cluster (NH₃)_n⁺(n=2～6) and ionic series of protonated ammonia clusters(NH₃)_nH⁺(n=2～15). At last, the experimental result is theoretically explained. Finally, a simple summary is done, and the main research achievement of this paper is given.