Clusters:  Structure, Energetics, and Dynamics of Intermediate States of Matter

Abstract

The field of cluster research can trace its origins back to the mid-nineteenth century when early studies of colloids, aerosols, and nucleation phenomena were reported. The field underwent a resurgence of interest several decades ago when well-defined clusters were observed in supersonic expansions that could be investigated using mass spectrometers. The advent of the laser provided a new dimension, enabling detailed spectroscopic observations through the probing of systems of varying size and degree of solvation. Modern interest derives from recognition that interrogating clusters provides a way of studying the energetics and dynamics of intermediate states of matter as cluster systems evolve from the gas toward the condensed state. Herein, we endeavor to highlight some of the significant advances which have been made during the past several decades that have led to a nearly explosive growth of interest in the field of cluster science. Finally, we conclude that the field will continue to expand through interests in basic phenomena, as well as through numerous applications of cluster research to fields ranging from catalysis to the quest for new cluster-assembled materials.

Broken-symmetry unrestricted hybrid density functional calculations on nickel dimer and nickel hydride

“…We use an exponent of 0.01 hartree for the Gaussian broadening function. We then use the molecular orbitals from the FONs calculation, after proper reordering, as initial guess for computing the 3 For Ni 2 and NiH, we use a broken-symmetry initial guess of the form: 3d 9 4s 1 ↑↑ϩ↓↓3d 9 4s 1 for singlet Ni 2 , 3d 9 4s 1 ↑↑ϩ↓↑3d 9 4s 1 for triplet Ni 2 and Ni 3d 9 4s 1 ↑↑ ϩ↓1s 1 H for NiH. As initial guess molecular orbitals we use those from the Ni atom calculations, sweeping through all unique positions of the holes in the 3d orbitals of Ni atom͑s͒, and enforcing the position of the hole͑s͒ with a maximum overlap condition.…”

“…For the PEC scans we use the medium grid, which gives for a 19-point B3LYP/AE PEC scan in the range 2-3. 2 and NiH, and dipole moment computed with B3LYP and FSLYP functionals using ''Stuttgart RSC ECP'' ECP and basis set with ''Ahlrichs Coulomb Fitting'' basis. The results from the calculations using CD fitting are reported in the ''cdfit'' columns, the result from the calculations not using CD fitting are reported in ''nocdfit'' columns, and the differences between the results from the calculations using CD fitting and the results from the ones not using CD fitting are reported under the ''cdfit err'' columns, with the percent relative errors in parentheses.…”

First Evidence of Rhombic (NaCl)2‐. Ab initio Reexamination of the Sodium Chloride Dimer Anion.

“…The former contain an extra electron localized primarily inside a cluster of polar molecules whose dipoles are directed toward the excess electron. 39 In the latter, an excess electron is localized outside the molecular framework and the dipoles are aligned constructively. SE systems are known to usually possess relatively large vertical electron detachment energies (VDE) and to undergo large geometrical rearrangements upon electron detachment because the dipoles directed toward one another are highly unfavorable in the absence of the electron.…”

Femtosecond dynamics of solvated oxygen anions. I. Bifurcated electron transfer dynamics probed by photoelectron spectroscopy

“…The addition of the solvent, which breaks the resonance, could yield a factor of 2 lengthening of 1 . Therefore, 1 is the overall time constant corresponding to ER and subsequent nuclear motion.…”

“…These microscopic solvation processes, which may involve energy redistribution, electron transfer, and vibrational predissociation, have been examined in a variety of ionic [1][2][3][4][5][6][7][8][9] and neutral [10][11][12][13][14] clusters.…”