An all-electron density functional theory study of the structure and properties of the neutral and singly charged M12 and M13 clusters: M = Sc–Zn

Abstract

The electronic and geometrical structures of the M12 and M13 clusters where M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn along with their singly negatively and positively charged ions are studied using all-electron density functional theory within the generalized gradient approximation. The geometries corresponding to the lowest total energy states of singly and negatively charged ions of V13, Mn12, Co12, Ni13, Cu13, Zn12, and Zn13 are found to be different from the geometries of the corresponding neutral parents. The computed ionization energies of the neutrals, vertical electron detachment energies from the anions, and energies required to remove a single atom from the M13 and M13(+) clusters are in good agreement with experiment. The change in a total spin magnetic moment of the cation or anion with respect to a total spin magnetic moment of the corresponding neutral is consistent with the one-electron model in most cases, i.e., they differ by ±1.0 μ(B). Exceptions are found only for Sc12(-), Ti12(+), Mn12(-), Mn12(+), Fe12(-), Fe13(+), and Co12(+).

The stabilization mechanism of titanium cluster

“…The computed spin multiplicities of the lowest energy structures for Ti n (n ¼3, 4, 5 and 7) agree with Castro et al [3] and Du et al [4]. For Ti 13 , the present result is consistent with Medina et al [6] and Wang et al [7]. However, almost no one explore the spin multiplicities of Ti 15 so far.…”

“…For Ti n opt (n ¼3, 4, 5, 7, 13, 15 and 19), each can be described as a distorted version of a higher symmetric structure, i.e., equilateral triangle (D 3h ), tetrahedron (T d ), triangular bipyramid (D 3h ), pentagonal bipyramid (D 5h ), icosahedron (I h ), sixfold icositetrahedron (D 6d ), two interpenetrating icosahedra (D 5h ) (Fig. 1), which agrees well with the previous results [2,3,6,7]. Based upon the standard structures, we have conducted comparative studies.…”

“…The occurrence of magnetism brings additional difficulties to obtain the ground states, for which we must consider the dense spin multiplicities to avoid trapping into local minima in the entire spin space. The understanding of geometric, electronic and magnetic properties of titanium clusters poses tremendous challenges both experimentally and computationally [1][2][3][4][5][6][7].…”

Photoelectron spectra and structure of the Mnn− anions (n = 2–16)

“…Special attention was paid by theoreticians to the neutral Mn 13 cluster which was found [32][33][34][35][36][37][38] to possess a slightly distorted icosahedral geometrical structure and a total spin magnetic moment of 3 µ B . Smaller neutral Mn n have also been the subject of a number of studies.…”

Correlation effects and orbital magnetism of Co clusters

“…Previous theoretical studies on the magnetic structure of transition-metal clusters [11][12][13][14][15][16][17][18][19][20][21] focus primarily on the spin moment due to the difficulties in estimating the orbital moment. The only theoretical study that addresses the orbital magnetic moment of pure clusters is focused on Co 2 , which is technically more treatable.…”