A Density Functional Analysis on Formation of Rubidium and Cesium Atomic Clusters in the Highest Spin State

2013 ◽  
Vol 86 (11) ◽  
pp. 1248-1255 ◽  
Author(s):  
Xuan Liu ◽  
Haruhiko Ito ◽  
Eiko Torikai
Keyword(s):  
Functional Analysis ◽  
Spin State ◽  
Density Functional ◽  
Atomic Clusters

Density functional theory studies of boron clusters with exotic properties in bonding, aromaticity and reactivity

2021 ◽  
Author(s):  
Dongbo Zhao ◽  
Xin He ◽  
Meng Li ◽  
Bin Wang ◽  
Chunna Guo ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Atomic Clusters ◽  
Functional Theory ◽  
Boron Clusters ◽  
Size And Structure

Atomic clusters are unique in many perspectives because of their size and structure features and are continuously being applied for different purposes.

Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms

2005 ◽  
Vol 894 ◽  
Author(s):  
Ofelia Oña ◽  
Victor E. Bazterra ◽  
María C. Caputo ◽  
Marta B. Ferraro ◽  
Julio Facelli
Keyword(s):  
Global Optimization ◽  
Density Functional ◽  
Atomic Clusters ◽  
Medium Size ◽  
Atomic Cluster ◽  
Approximate Methods ◽  
Functional Theory ◽  
Parallel Genetic Algorithms ◽  
Applied Technology ◽  
Optimization Schemes

AbstractThe study of the structure and physical properties of atomic clusters is an extremely active area of research due to their importance, both in fundamental science and in applied technology. For medium size atomic clusters most of the structures reported today have been obtained by local optimizations of plausible structures using DFT (Density Functional Theory) methods and/or by global optimizations in which much more approximate methods are used to calculate the cluster’s energetics. Our previous work shows that these approaches can not be reliably used to study atomic cluster structures and that approaches based on global optimization schemes are needed. In this paper, we report the implementation and application of a parallel Genetic Algorithm (GA) to predict the structure of medium size atomic clusters.

scholarly journals Crystal structure and spectroscopic characterization of a cobalt(II) tetraazamacrocycle: completing a series of first-row transition-metal complexes

2017 ◽  
Vol 73 (8) ◽  
pp. 620-624 ◽  
Author(s):  
Katherine M. Van Heuvelen ◽  
Isabell Lee ◽  
Katherine Arriola ◽  
Rilke Griffin ◽  
Christopher Ye ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Spin State ◽  
Density Functional ◽  
Cobalt Complex ◽  
Chloride Ion ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Chloride Dihydrate ◽  
Pyramidal Geometry ◽  
A Minor

The tetraazamacrocyclic ligand 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane (TMC) has been used to bind a variety of first-row transition metals but to date the crystal structure of the cobalt(II) complex has been missing from this series. The missing cobalt complex chlorido(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane-κ4 N)cobalt(II) chloride dihydrate, [CoCl(C14H32N4)]Cl·2H2O or [CoIICl(TMC)]Cl·2H2O, crystallizes as a purple crystal. This species adopts a distorted square-pyramidal geometry in which the TMC ligand assumes the trans-I configuration and the chloride ion binds in the syn-methyl pocket of the ligand. The CoII ion adopts an S = 3 \over 2 spin state, as measured by the Evans NMR method, and UV–visible spectroscopic studies indicate that the title hydrated salt is stable in solution. Density functional theory (DFT) studies reveal that the geometric parameters of [CoIICl(TMC)]Cl·2H2O are sensitive to the cobalt spin state and correctly predict a change in spin state upon a minor perturbation to the ligand environment.

scholarly journals Structural Evidence of Spin State Selection and Spin Crossover Behavior of Tripodal Schiff Base Complexes of tris(2-aminoethyl)amine and Related Tripodal Amines

2020 ◽  
Vol 6 (2) ◽  
pp. 28
Author(s):  
Greg Brewer
Keyword(s):  
Schiff Base ◽  
Spin State ◽  
Density Functional ◽  
Spin Crossover ◽  
Bimodal Distribution ◽  
Structural Features ◽  
Schiff Base Complexes ◽  
Mononuclear Iron ◽  
Experimental Values ◽  
State Selection

A review of the tripodal Schiff base (SB) complexes of tris(2-aminoethyl)amine, Nap(CH2CH 2NH2)3 (tren), and a few closely related tripodal amines with Cr(II), Mn(III) (d4), Mn(II), Fe(III) (d5), Fe(II) (d6), and Co(II) (d7) is provided. Attention is focused on examination of key structural features, the M-Nimine, M-Namine, or M-O and M-Nap bond distances and Nimine-M-N(O) bite and C-Nap-C angles and how these values correlate with spin state selection and spin crossover (SCO) behavior. A comparison of these experimental values with density functional theory calculated values is also given. The greatest number, 132, of complexes is observed with cationic mononuclear iron(II) in a N6 donor set, Fe(II)N6. The dominance of two spin states, high spin (HS) and low spin (LS), in these systems is indicated by the bimodal distribution of histogram plots of Fe(II)-Nimine and Fe(II)-Nazole/pyridine bond distances and of Nimine–Fe(II)-Nazole/pyridine and C-Nap-C bond angles. The values of the two maxima, corresponding to LS and HS states, in each of these histograms agree closely with the theoretical values. The iron(II)-Nimine and iron(II)-Nazole/pyridine bond distances correlate well for these complexes. Examples of SCO complexes of this type are tabulated and a few of the 20 examples are discussed that exhibit interesting features. There are only a few mononuclear iron(III) cationic complexes and one is SCO. In addition, a significant number of supramolecular complexes of these ligands that exhibit SCO, intervalence, and chiral recognition are discussed. A summary is made regarding the current state of this area of research and possible new avenues to explore based on analysis of the present data.

Density Functional Analysis of Ancillary Ligand Electronic Contributions to Metal-Mediated Enediyne Cyclization

2009 ◽  
Vol 48 (9) ◽  
pp. 3926-3933 ◽  
Author(s):  
Aurora E. Clark ◽  
Sibaprasad Bhattacharryya ◽  
Jeffrey M. Zaleski
Keyword(s):  
Functional Analysis ◽  
Density Functional ◽  
Ancillary Ligand
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