Structural evolution and properties of subnanometer Tc(n) (n = 2-15) clusters.
All-electron scalar relativistic calculations of the geometric and electronic structures of neutral subnanometer Tc(n) (n = 2-15) clusters have been performed using spin-polarized density functional theory. It is shown that the structural evolution of Tc(n) clusters from n = 3 to n = 8 is similar to Mn clusters, which also belong to the group of VIIB transition metals. The calculated binding energy per atom varies gradually from 0.65 eV for Tc(2) to 2.35 eV for Tc(15). The computed electron affinity and ionization potential follow the classical electrostatic metallic droplet model for clusters larger than Tc(6) and converge asymptotically to the experimental value of the bulk Tc work function. A study of the kinetic stability of Tc clusters in terms of the second difference of binding energies and the energy gap between the frontier orbital states predicts Tc(3)(D(3h)), Tc(4)(T(d)), Tc(6)(O(h)), Tc(12)(I(h)), and Tc(13)(I(h)) to be the most stable clusters. Vibrational spectra of Tc clusters are also provided for further experimental identification.
Department of Chemistry, University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154, USA. weckp@unlv.nevada.edu
Philippe F
PF
Weck
Eunja
E
Kim
Frédéric
F
Poineau
Kenneth R
KR
Czerwinski