Structure, Bonding, and Stability of Small Boron−Lithium Clusters

Abstract

Structures and energies for BLi n (n = 1−3) are investigated with various basis sets and with different levels of theory, including single reference- and multireference-based correlated methods up to QCISD(T)/6-311+G(3df)//MP2(full)/6-311+G(d), MCQDPT2/6-311+G(2df)// CASSCF/6-31G(d), G2, and G2(MP2) theory. BLi (3Πg), BLi2 (2 B 2), and BLi3 (C 2 v) are global minima with respective atomization energies of ∼26, 55, and 95 kcal/mol. Their structures are not strongly influenced by the size of the basis set nor by the method of electron correlation employed. Energetics for low-lying excited states of BLi and BLi2 were determined. The dissociation energies obtained with B3LYP/6-31G(d) theory are in excellent agreement with those obtained with the highest levels of theory.

The high stability of boron-doped lithium clusters Li5B, Li6B+/− and Li7B: A case of the phenomenological shell model

“…1, whereas their Cartesian coordinates are listed in Table S1 of the Supplementary material. For Li 5 B, our findings are in good agreement with previous studies [18,20] that the high symmetry structure (C 4v , 1 A 1 ) is the most stable isomer. At the B3LYP/aug-cc-pVTZ level, the two structures having C 2v ( 2 A 1 ) and D 3h ( 2 A 0 1 ) point groups turn out to be transition structures having the same energetic content, and are $1.5 kcal/ mol higher as compared to the global minimum.…”

“…For the neutral radical Li 7 B, our calculated results are also consistent with previous reports [18,20] that the pentagonal bipyramid structure (D 5h , 1 A 0 1 ) is the global equilibrium structure. The C 3v structure of Li 7 B ( 1 A 1 ) is found to be the second lowest-energy isomer with a relative energy of 4.3 kcal/mol (at the CCSD(T)/aug-cc-pVTZ level).…”

“…A large number of the experimental and theoretical studies have been performed on pure lithium clusters [13,14] as well as on doped lithium clusters by many groups [15][16][17]. Theoretical investigations for boron-doped lithium clusters in both neutral and cationic states were performed by Nguyen et al [18,19] and Li et al [20,21]. Li et al found that the neutral Li 5 B was pointed out to have a high stability in the series of Li n B clusters (n = 1-7), whereas the cation Li 6 B + was found to have a high stability within the Li n B + cationic cluster state.…”

Thermochemical properties, electronic structure and bonding of mixed lithium boron clusters (BnLi, n=1–8) and their anions

“…The lowest-lying excited state is the low spin 1 R + [51,52] with the corresponding singlet-triplet gap amounting to 5.8 kcal/mol (CCSD(T)). The bond dissociation energy D 0 ( 3 P) is calculated at 24.1 kcal/mol at the same level, that agrees with the values given in previous reports using different methods, namely 26.5 kcal/ mol by G2(MP2), 26.6 kcal/mol by QCISD [52] and 27.2 kcal/mol by QCISD(T)/6-311+G(2df)//MP2/6-311+G(d) [53]. The B3LYP/6-311+G(d) bond length of the 3 P state is 2.131 Å, that is 0.267 Å shorter than that of the excited state 1 R + (2.398 Å).…”

Designing nonlinear optical molecule by incorporating the planar tetracoordinate unit NAl4- or CAl42- into decaborane B10H14

“…The honeycombed decaborane B 10 H 14 without a weak°exible con¯guration caught our attentions, due to its aesthetically appealing structure and unique bonding features. [27][28][29][30] The B 10 H 14 possess four equivalent electron-de¯cient terminal H atoms (see Fig. 1) and exhibits a wide range of properties, and its complexes with ions and atoms have been studied experimentally 31,32 and theoretically.…”