NIST Inorganic Crystal Structure Database (NIST ICSD) Data Field Specifications and Conventions

2019 NIST Inorganic Crystal Structure Database (NIST ICSD) Data Field Specifications and Conventions PREPARED BY Xiang Li Material Measurement Laboratory National Institute of Standards and Technology Gaithersburg, Maryland 20899 Table of Contents 1. Introduction .................................................................................................................................................................... 3 2. The Data Fields ................................................................................................................................................................ 3 2.1 Anisotropic Thermal Parameters ............................................................................................................................ 3 2.2 ANX Formula ........................................................................................................................................................... 4 2.3 Atomic Site .............................................................................................................................................................. 4 2.4 Author Name ........................................................................................................................................................... 5 2.5 Authors’ Structure ................................................................................................................................................... 5 2.6 Centering ................................................................................................................................................................. 5 2.7 Chemical Name ....................................................................................................................................................... 6 2.8 Coden / Journal ....................................................................................................................................................... 6 2.9 Collection Code ....................................................................................................................................................... 7 2.10 Comments ............................................................................................................................................................... 7 2.11 Crystal Class............................................................................................................................................................. 7 2.12 Crystal System ......................................................................................................................................................... 7 2.13 Density .................................................................................................................................................................... 8 2.14 Element Count ........................................................................................................................................................ 8 2.15 Formula Weight ...................................................................................................................................................... 8 2.16 Inversion Center ...................................................................................................................................................... 8 2.17 Isotropic Thermal Parameters ................................................................................................................................ 9 2.18 Laue Class ................................................................................................................................................................ 9 2.19 Mineral Group ......................................................................................................................................................... 9 2.20 Mineral Name ....................................................................................................................................................... 10 2.21 Mineral Origin ....................................................................................................................................................... 10 2.22 Minimal Distance .................................................................................................................................................. 10 2.23 Powder Diffraction File (PDF) Number ................................................................................................................. 11 2.24 Pearson Symbol ..................................................................................................................................................... 11 2.25 Polar Axis ............................................................................................................................................................... 12 2.26 Pressure................................................................................................................................................................. 12 2.27 Reduced Cell .......................................................................................................................................................... 12 2.28 R Value .................................................................................................................................................................. 12 2.29 Space Group .......................................................................................................................................................... 12 2.30 Standard Remarks ................................................................................................................................................. 13 2.31 Standardized Structure ......................................................................................................................................... 13 2.32 Structure Type ....................................................................................................................................................... 14 1 2.33 Structural Formula ................................................................................................................................................ 14 2.34 Sum Formula ......................................................................................................................................................... 14 2.35 Temperature ......................................................................................................................................................... 15 2.36 Unit Cell ................................................................................................................................................................. 15 2.37 Wyckoff / Multiplicity ........................................................................................................................................... 15 2.38 Wyckoff Sequence ................................................................................................................................................ 15 2.39 Z ............................................................................................................................................................................. 15 2 1. Introduction The NIST Inorganic Crystal Structure Database (NIST ICSD) is a comprehensive collection of bibliographic, chemical, and crystallographic information covering non-organic materials (including inorganics, ceramics, minerals, pure elements, metals, and intermetallic systems) containing over 210,000 entries and covering the literature from 1913. NIST ICSD database contains crystallographic information including unit cell data, space group information, Pearson Symbol, formula units per cell, and atomic positions (thermal parameters when available) for full-structure entries, and additional information such as standardized cell and atomic coordinates, reduced cell, structure type, locality for minerals, temperature/pressure of data collections, and editorial remarks for better characterization of the materials. 2. The Data Fields Specifications and conventions used for the NIST ICSD data fields are described in the following sections. 2.1 Anisotropic Thermal Parameters U, B, Beta are labels used to designate the anisotropic thermal parameters in the Database. These are the anisotropic atomic displacement components which appear in the corresponding structure-factor term listed below (h, k, l are the Miller indices, and a*, b*, c* are the reciprocal-space cell lengths.). • Database label U (unit: angstrom squared) 2 2 ∗2 2 ∗2 2 ∗2 ∗ ∗ ∗ ∗ ∗ ∗ exp⁡(−2휋 (푈11ℎ 푎 + 푈22푘 푏 + 푈33ℎ푙 푐 + 2푈12ℎ푘푎 푏 + 2푈13ℎ푙푎 푐 + 2푈23푘푙푏 푐 )) • Database label B (unit: angstrom squared) 1 exp⁡(− (퐵 ℎ2푎∗2 + 퐵 푘2푏∗2 + 퐵 푙2푐∗2 + 2퐵 ℎ푘푎∗푏∗ + 2퐵 ℎ푙푎∗푐∗ + 2퐵 푘푙푏∗푐∗)) 4 11 22 33 12 13 23 • Database label Beta (unitless) 3 2 2 2 exp⁡(−(훽11ℎ + 훽22푘 + 훽33푙 + 2훽12ℎ푘 + 2훽13ℎ푙 + 2훽23푘푙)) In the Database, the anisotropic U, B and Beta labels for thermal data are followed by 6 coefficients [for example, (U11 U22 U33 U12 U13 U23), in equation for label U above]. Further details on the nomenclature can be found in the IUCr Report on atomic displacement parameter nomenclature (K.N. Trueblood, H.-B. Burgi, H. Burzlaff, J.D. Dunitz, C.M. Gramaccioli, H.H. Schulz, U. Shmueli, S.C. Abrahams, Atomic displacement parameter nomenclature, Report of a subcommittee on atomic displacement parameter nomenclature,

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