Crystalmaker add atoms
Considering structures of metals, including those at high temperature and pressure, the body-centered cubic (bcc) structure is as common as the cubic close-packed (ccp) and hexagonal close-packed (hcp) structures. Earlier books have missed the beauty of the general scheme for crystal structures. Two appendices cover the literature, general considerations of solids, and predictions of structures. Chapter 12 provides a summary and covers the interpretation of structures and assignment of notation. Intermetallic compounds are covered in Chapter 9, silica and silicates are covered in Chapter 10, and selected organic compounds are covered in Chapter 11. Chapter 8 deals with compounds involving unusual combinations of layers and multiple layers, cases where one layer is occupied by more than one of the A, B or C packing positions. Compounds in Chapter 7 have ions (or atoms) in various combinations of P, T and O layers, including cases where all PTOT layers are occupied. Chapter 6 deals with structures based on close-packed ions (or atoms) in P layers with other ions (or atoms) in one or both tetrahedral layers (PT or PTT). Chapter 5 deals with structures (PO) based on closepacked ions (or atoms) in P layers and other ions (or atoms) in O layers. Chapter 4 treats metals, other elements and compounds with structures based on close-packing of P layers. Chapters 1 to 3 cover crystal systems and classes, symmetry, and terminology used in describing crystal structures. The deformation commonly makes little change in the PTOT notation and the relationships can be seen.īackground is presented in early chapters for those interested in solids who are not experts in crystallography. Small deformations in a crystal structure can change the space group and the crystallographic notation so that the relationship between a slightly deformed structure and the original structure is not apparent. The chemistry and properties are dependent on the symmetry of sites and the coordination number of atoms or ions. The notation system emphasizes the environment of individual ions or molecules. This approach provides insight into similarities and differences among structures. The scheme and notation are explained and applied. This book presents a unifying scheme using a very simple system of notation. For many of these, labels for layers or atoms have been added to identify important features and aid in visualizing the structure. Figures have been selected and prepared carefully. The system and the notation reveal similarities and differences among structures. These structures are encountered for many thousands of compounds. Approximately 300 structures are described using the PTOT notation. The simple notation gives important information about the structure. This book is intended for these individuals. Those working with crystal structures in chemistry, mineralogy, geology, metallurgy, and material science need a simple, widely applicable, system. Earlier books have recognized only part of nature’s system for efficient packing in crystals. The PTOT system and the notation presented are important in teaching crystal structures in any area concerned with such structures and with solid state applications.
The spacing is also quite regular, determined by the geometry of octahedra and tetrahedra. However, none has recognized that there is a general scheme involving packing (P), octahedral (O), and tetrahedral (T) sites occurring in layers, in the sequence PTOT. 9 8 7 6 5 4 3 2 1 īooks on crystal structures have long recognized the importance of close packing in many crystal structures and the roles of tetrahedral and octahedral sites in such structures are well known. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer ScienceþBusiness Media, Inc., 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. ß 2006 Springer ScienceþBusiness Media, Inc. Douglas Shih-Ming Ho University of Pittsburgh Pittsburgh, PA USA Structure and Chemistry of Crystalline Solidsīodie E.