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This paper reports theoretical design on several types of novel superatom compounds, and systematical study on structures and properties of these superatom compounds. The main contribution is as follows,（1） Our systematic calculations on BF4-M （M = Li, FLi2, OLi3, NLi4） have theoretically predicted a new type of superhalogen-（super）alkali compounds, at the MP2/6-311+G（3df） level. The preferred orientations between polyhedral BF4 and Li atom, linear FLi2, planar OLi3, and polyhedral NLi4, are side-point, face-side, face-face, and face-face, respectively. The interaction between superhalogen BF4 and different shaped （super）alkali M is found to be strong and ionic in nature. Bond energies of these BF4-M species are in the range of 200.0 226.7 kcal/mol at the CCSD（T）/6-311+G（3df） level, which are much larger than the traditional ionic bond energy of 130.1 kcal/mol of FLi. As a result of high electron affinity of BF4, different from the alkali halides, the BF4-M compounds prefer to dissociate into ions rather than neutral fragments. It is found that both the HOMO-LUMO gaps and binding energies per atom of BF4-M show decreasing tendencies with increasing size of the M subunit. As regards the NLO properties, both polarizabilities and the first hyperpolarizabilities of BF4-M apparently increase with M becoming larger. However, the introduction of superhalogen leads to decreasedβ0 value, and furthermore, the larger the superhalogen subunit, the less theβ0 value of BF4-M.（2） Two types of small aluminum clusters-（super）atom compounds, Al3-X （X=F, LiF2, BeF3, BF4） and Al3-M （M = Li, FLi2, OLi3, NLi4）, are theoretically predicted, at the MP2/6-311+（3df） computational level. For Al3-X species, the preferred orientation between Al3 and F atom is point-point, while between Al3 and different shaped superhalogens LiF2, BeF3, and BF4 are all side-point. For Al3-M species, the preferred orientations between Al3 and Li, FLi2, OLi3, and NLi4 are face-point, face-side, side-face and side-face, respectively. Large bond energies and the NBO and AIM analyses show that there are strong interactions between Al3 and （super）halogen and between Al3 and （super）alkalie. However, as a result of the shell closure of Al3+ cation, the bond energies of Al3-X are larger than those of the Al3-M compounds. Furthermore, we found that the bond energy is closely correlated to the bonding mode type; for isomers of Al3-superhalogen with different bonding modes, the bond energies order is ff type > ss type > ps type, and for Al3-superalkalies the bond energies order is sf type > fs type > ss type, respectively.The HOMO orbital of each Al3-X and Al3-M species is a doubly occupied, delocalizedσbonding orπbonding orbital on a Al3 ring, consequently, Al3-X and Al3-M compounds are aromatic, and their aromaticity can be confirmed by the negative NICS values. We find that when the geometrical deformation of Al3 is very large, the aromaticities of Al3-X and Al3-M molecules may disappear, but in the case of maintaining aromaticity, the Al3- ring of Al3-M may have greater deformation than the Al3+ ring of Al3-X.We hope that the principles obtained from this study may, in the future, provide a useful guidance for superatom researches and new materials designing.
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