Density Functional Theory Studyby Of Metal Nitride Clusters Adsorbing H

M-N-H (M is the metal elements of I-IV and transition metals) series metal complexes hydrogen storage materials was concerned in recent years due to the higher hydrogen storage quality percentage density and certain reversible. Therefore, in this paper, the ground state electronic structure, vibration spectra and the clusters kinetic stability of Mg3N2clusters adsorbed H and Li3N clusters adsorbed H are studied by quantum chemistry methods.Using the density functional theory (B3LYP) with6-311G*basis sets to study the possible geometrical structure, relative stabilities of Mg3N2Hm(m=1-4) and (Mg3N2)nHm (n=2-4,m=1-2) clusters are studied by using the density functional theory (B3LYP) with6-311G*basis sets. For the most stable isomers of Mg3N2Hm(m=1-4) and (Mg3N2)nHm (n=2-4,m=1-2) clusters, the electronic structure,bonding characteristics, charge distribution, vibrational properties and relative stabilities are analyzed. When the number of the adsorbed H atoms less than that of N atoms, it mainly forms-NH group. And then some H atoms are adsorbed by the-NH groups and it forms-NH2groups while some other H atoms are adsorbed by Mg forming MgH when all the N atoms bond as-NH. H atom is easialy adsorped on N atom which is projecting and contains the lone pair electrons. Due to the repulsion between the lone pair electrons, the adsorption positions of H atoms were away from each other. The N-H in cluster showed covalent interaction, where the Mg-H showed ionic bond interaction. The properties of-NH and-NH2group are consistent with that of crystals, so the cluster can describe the behavior of the hydrogen storage in crystals.Using the density functional theory (B3LYP) with6-311G*basis sets to study the possible geometrical structure and relative stabilities of Li3NHm(m=1-4) and (Li3N)nHm (n=2-5,m=1-2) clusters. For the most stable isomers of Li3NHm(m=1-4) and (Li3N)nHm (n=2-5,m=1-2) clusters, the electronic structure,vibrational properties, bonds properties and relative stabilities are analyzed. In the Li3N clusters, hydrogen is manly stored in the N location which formed-NH and-NH2, and may also be stored in the Li location. Absorping hydrogen in this system is most likely to form-NH,then the H atom may combine with Li to form LiH structure, it continues to store the hydrogen,the-NH group may be formed-NH2group. In the clusters, H atom is easily adsorbed on the4coordination N which contains the lone pair electrons to form-NH. Two-NH group showed away trend due to the repulsion between the lone pair electrons. Li atoms and-NH group and-NH2group showed a strong ionic interaction, whereas-NH and-NH2showed covalent.