Comment on ‘‘Effect of surface reconstruction on stability and reactivity of Si clusters’’

Abstract

Unclassified 2a. SECURITY CLASSIFICATION. AUTHORITY 3. DISTRIBUTION/AVAILABILITY OF REPORT Approved for public release; distribution 2b. DECLASSIFICATION / DOWNGRADING SCHEDULE unlimited 4. PERFORMING ORGANIZATION REPORT NUMBER(S) S. MONITORING ORGANIZATION REPORT NUMBER(S) UBUFFALO/DC/9 1/TR-47 6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Depts. Chemistry & Physics I (If applicable)

Structure of the Si45 cluster

“…These were discovered serendipitously in attempting to reproduce Kaxiras' results using classical potentials. 21 Both have full Td symmetry and are abbreviated as T1 and T2 in Table I. The T1 structure is shown in Fig.…”

“…This is borne out by Tomanek and Schluter's original comparison with the local density approximation (LOA) results with small clusters, and by our results for SilO ' All of the above clusters are stable under the classical potentials listed above, with the exception ofTl and T2. 21 The KP potential shows Tl to be the preferred structure, whereas the Tersoffmethod indicates T2. This is consistent with the stated aims of the potentials, in that T2 may in some ways be considered to have a larger coordination number, and in any event, the angles are far from tetrahedral.…”

“…In a Comment on Kaxiras' work,21 we have proposed two additional structures which have complete tetrahedral symmetry. These resemble Kaxiras' in that they all have a tetrahedrally situated central atom, but are surrounded by what we describe as reconstructed clusters rather than a reconstructed surface.…”

Surface-reconstruction-induced geometries of Si clusters

“…(2) If the clusters of various sizes possess no special geometric features, as the simulations based on various methodologies suggest [46][47][48][49] , then it is difficult to explain the dramatic changes in reactivity and the existence of the magic numbers.…”

Structures of Silicon Clusters

“…Recently, the covalent semiconductor clusters have received substantial attention because of their expected importance in microelectronics industry [2][3][4][5][6][7][8][9][10][11][12]. Since silicon is technologically the most important semiconductor material, these studies have attempted to understand the evolution of its structural and optical properties as a function of cluster size.…”