Structures and Electronic Properties of Beryllium Atom Encapsulated in Si_n^(0,−1) (n = 2−10) Clusters

Abstract

The equilibrium geometries and energies of neutral BeSi(n) (n = 2-10) species and their anions have been studied at the highest level of Gaussian-3 (G3) theory. The results reveal that the ground-state structures of these clusters are Be-encapsulated in silicon cages with n >or= 8. The reliable adiabatic electron affinities of BeSi(n) have been predicted to be 1.68 eV for BeSi(2), 1.87 eV for BeSi(3), 2.33 eV for BeSi(4), 2.29 eV for BeSi(5), 2.11 eV for BeSi(6), 2.37 eV for BeSi(7), 2.95 eV for BeSi(8), 2.74 eV for BeSi(9), and 1.92 eV for BeSi(10). The dissociation energies of Be atom from BeSi(n), Si atom from BeSi(n), and Si atom from Si(n) clusters have also been calculated, respectively, to examine relative stabilities. The trend of stability of BeSi(n) changed with n is converse to that of Si(n) when n <or= 7. From n >or= 8, the encapsulated Be atom in silicon cages not only results in an identical trend for stability of BeSi(n) and Si(n) but also improves the stability of Si(n) clusters.

Small copper-doped silicon clusters CuSin (n = 4–10) and their anions: structures, thermochemistry, and electron affinities

“…The C s symmetry 6d of 2 A′ state can be viewed as attaching a Si atom to the ground state structure of anion CuSi 7 − . The D 2h symmetry 6e Cu-body-centered cubic structure of 2 B 1u state, similar to the ground state structure of BeSi 8 [5], belongs to the Bfourth type^. Energetically, the 6a structures are more stable than those of 6b, 6c, 6d, and 6e by 0.…”

“…Energetically, the 5a structure is more stable than that of 5c by 0.37 and 0.32 eV at the G4 and the CCSD(T) level, respectively. The C s symmetry structure 5b of 2 A′ state, analogous to the ground state structure of BeSi 7 [5], belongs to a Bfourth type^. At the CCSD(T) level, it is less stable in energy than that of 5a by 0.22 eV, but more stable by 0.18 eV at the G4 level.…”

“…Silicon-based clusters have been investigated both experimentally and theoretically because they enable not only miniaturization of electronic devices but also exert control over a wide variety of properties by changing size, shape, and composition [1][2][3][4][5][6][7][8][9][10]. In particular, doping a transition metal atom into silicon clusters can alter the structure of the silicon cage, reduce the chemical activity of the surface dangling bonds and enhance stability [11][12][13][14][15][16][17][18][19][20].…”

Europium-doped silicon clusters EuSi n (n = 3–11) and their anions: structures, thermochemistry, electron affinities, and magnetic moments

“…Like carbon atoms, they can appear with sp, sp 2 , or sp 3 hybridization in compounds [11,12]. However, a wide variety of experimental [13][14][15] and theoretical [16][17][18] research works elucidated that doping a suitable foreign atom inside silicon clusters can not only enhance the stability, but also influence profoundly the electron properties of these complexes. In particular, the examples of encapsulating a transition metal (TM) atom insider silicon clusters as building blocks of cluster-assembled materials with novel magnetic, electronic, and possibly optical properties are numerous.…”

Geometrical and electronic structure of the Ba-doped Sin (n=1–12) cluster: A density functional study

“…The research on the silicon-based clusters is of particular interest, due to their numerous technological applications and the intensive ongoing efforts to reduce sizes in nanomaterials [7][8][9]. In current semiconductor industry, nanoelectronic devices are often fabricated by lithographic techniques.…”