Principles of isomer stability in small clusters

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{
  "metadata": {
    "is_last": true, 
    "version": 1, 
    "title": "Principles of isomer stability in small clusters", 
    "keywords": [
      "SNSF", 
      "CSCS", 
      "atomic clusters", 
      "DFT"
    ], 
    "description": "In this work we study isomers of several representative small clusters to find principles for their stability. Our conclusions about the principles underlying the structure of clusters are based on a huge database of 44'000 isomers generated for 59 different clusters on the density functional theory level by Minima Hopping. We explore the potential energy surface of small neutral, anionic and cationic isomers, moving left to right across the third period of the periodic table and varying the number of atoms n and the cluster charge state q (X^q_n, with X={Na, Mg, Al, Si, Ge}, q=-1,0,1,2). We use structural descriptors such as bond lengths and atomic coordination numbers, the surface to volume ratios and the shape factor as well as electronic descriptors such as shell filling and hardness to detect correlations with the stability of clusters. The isomers of metallic clusters are found to be structure seekers with a strong tendency to adopt compact  shapes. However certain numbers of atoms can suppress the formation of a nearly spherical metallic clusters. Small non-metallic clusters typically also do not adopt compact spherical shapes for their lowest energy structures. In both cases spherical jellium models are not any more applicable. Nevertheless for many  structures, that have frequently a high degree of symmetry, the Kohn-Sham eigenvalues are bunched into shells and if the available electrons can completely fill such shells, a particularly stable structure can result. We call such a cluster whose shape gives rise to shells that can be completely filled by the number of available electrons an optimally matched cluster, since both the structure and the number of electrons must be special and match. In this way we can also explain the stability trends for covalent silicon and germanium cluster isomers, whose stability was previously explained by the presence of certain structural motifs. Thus we propose a unified framework to explain trends in the stability of isomers and to predict their structure for a wide range of small clusters.\n\nThis data record contains structure coordinates (compressed file all_minima_xyz_structures.tar.gz) of all minima found by the minima hopping method for all neutral and charged clusters, that are 43606 different structures. The python dictionary all_minima_names.npy stores all minima names. The python dictionary all_minima_data.npy stores all structural and electronic properties calculated for all minima. The jupyter notebook all_minima_data_analysis.ipynb helps the reading of the all_minima_names.npy and all_minima_data.npy python dictionaries.", 
    "license": "Creative Commons Attribution 4.0 International", 
    "references": [
      {
        "url": "http://dx.doi.org/10.1039/D2MA01088G", 
        "type": "Journal reference", 
        "citation": "G. Fisicaro, B. Schaefer, J.A. Finkler and S. Goedecker,  Mater. Adv. 4, 1746-1768 (2023)", 
        "comment": "Paper in which data are generated, analyzed and discussed.", 
        "doi": "10.1039/D2MA01088G"
      }
    ], 
    "doi": "10.24435/materialscloud:46-nr", 
    "conceptrecid": "1675", 
    "publication_date": "Mar 06, 2023, 10:40:06", 
    "edited_by": 960, 
    "_oai": {
      "id": "oai:materialscloud.org:1676"
    }, 
    "contributors": [
      {
        "affiliations": [
          "Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (CNR-IMM), Z.I. VIII Strada 5, I-95121 Catania, Italy"
        ], 
        "email": "Giuseppe.Fisicaro@imm.cnr.it", 
        "familyname": "Fisicaro", 
        "givennames": "Giuseppe"
      }, 
      {
        "affiliations": [
          "Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland"
        ], 
        "familyname": "Schaefer", 
        "givennames": "Bastian"
      }, 
      {
        "affiliations": [
          "Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland"
        ], 
        "familyname": "Finkler", 
        "givennames": "Jonas A."
      }, 
      {
        "affiliations": [
          "Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland"
        ], 
        "familyname": "Goedecker", 
        "givennames": "Stefan"
      }
    ], 
    "owner": 960, 
    "license_addendum": null, 
    "mcid": "2023.36", 
    "_files": [
      {
        "size": 44126079, 
        "checksum": "md5:d8e75cc8c91d8143fc2ed89259a9741e", 
        "description": "Structure coordinates of all minima found by the minima hopping method for all neutral and charged clusters, that are 43606 different structures.", 
        "key": "all_minima_xyz_structures.tar.gz"
      }, 
      {
        "size": 963203, 
        "checksum": "md5:d971ad96e6f40c2840b061aa65464e97", 
        "description": "A python dictionary which stores all minima names.", 
        "key": "all_minima_names.npy"
      }, 
      {
        "size": 27753326, 
        "checksum": "md5:5de9f0897b2c9dd152857e8219096d83", 
        "description": "A python dictionary which stores all structural and electronic properties calculated for all minima.", 
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      }, 
      {
        "size": 20250, 
        "checksum": "md5:3e2c0e491c8576ce7614c3676e87e6fb", 
        "description": "A jupyter notebook which helps the reading of the all_minima_names.npy and all_minima_data.npy python dictionaries.", 
        "key": "all_minima_data_analysis.ipynb"
      }
    ], 
    "id": "1676", 
    "status": "published"
  }, 
  "revision": 3, 
  "updated": "2023-04-03T16:00:46.227990+00:00", 
  "created": "2023-03-06T09:31:18.441599+00:00", 
  "id": "1676"
}