Coordinates of the low-lying energy Agn isomers and the Agn-Tyr complexes
Data files
Dec 05, 2023 version files 35.86 KB
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datosAgn.xyz
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datosAgnTyr.xyz
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README.md
Abstract
Noble metal clusters with a size around the Fermi wavelength of electrons display quantum confinement effects and properties such as photoluminescence, two-photon absorption, and second and third-harmonic generation. As a result of these unique features, noble metal clusters are increasingly gaining popularity in optics and catalysis. Being highly reactive, it is standard practice to use capping agents to stabilize them.
This dataset contains the structural parameters for the low-lying energy Agn isomers and the Agn-Tyr complexes from n = 3–12, all fully optimized at the B3PW91 functional combined with the def2-TZVP basis set. The structural parameters were obtained using a global search strategy combined with DFT calculations to explore the potential energy surface of clusters of atoms and molecules.
Methods
We determine the putative global minima for the bare Agn (n = 3–12) clusters and the corresponding Agn-Tyr complexes via the GLobal Optimization of MOlecular Systems (GLOMOS). GLOMOS is a code written in Python that, through different strategies, can explore the potential energy surface of atomic and molecular clusters by evaluating the energy through electronic structure codes. The global optimization strategy choice was a stochastic approach. GLOMOS generates trial structures with random atomic coordinates, ensuring all the atoms meet a proximity criterion and form a bonded assembly. To minimize the possibility of collapse into a funnel associated with a dominant morphology, GLOMOS generates trial structures with different morphological patterns. GLOMOS identifies and discriminates the equivalent configurations via the Ultrafast Shape-Recognition Algorithm with Mass Ponderation (USRAMP).
The local optimization of the test structures Agn was done in two steps. All trial structures were fully optimized without symmetry constraints in the first stage using the B3PW91 hybrid functional with the LanL2DZ basis set. This functional-basis combination has delivered structural and electronic results in good agreement with the experimental data for small Ag naked clusters. In the second stage, after the similarity discrimination process, the final structures were again fully optimized at the B3PW91 functional with the def2-TZVP basis set. The highest multiplicities were not explored because the lowest spin state in small silver clusters is the ground state. A harmonic frequency analysis was also performed to verify a stationary local minimum for all the optimized structures. The punctual group for each cluster was determined using the SYVA program and the symmetry analyzer module included in the Python Materials Genomics library.
On the other hand, the strategy to find the most energetically favorable Agn-Tyr (n = 3–12) complexes consists of fixing the putative global minimum (GM) of each Agn cluster at the center of a coordinate system and trying different binding sites for tyrosine. For each silver cluster, 30n possibilities were estimated by randomly changing the binding site and the spatial orientation of the molecule in its Euler angles. All the candidate Agn-Tyr complexes thus built were fully optimized at the B3PW91/def2-TZVP level, including the Grimme D3 dispersion scheme.
Usage notes
Use Molden, VESTA (Visualization for Electronic and STructural Analysis), Avogadro, or any molecular visualization program.