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Crystal Engineering
Crystal engineering studies the design and synthesis of solid-state structures with desired properties through deliberate control of Intermolecular force, intermolecular interactions. It is an Interdisciplinarity, interdisciplinary academic field, bridging solid-state and supramolecular chemistry. The main engineering strategies currently in use are hydrogen bond, hydrogen- and Halogen bond, halogen bonding and coordination bonding. These may be understood with key concepts such as the supramolecular synthon and the secondary building unit. History of term The term 'crystal engineering' was first used in 1955 by R. Pepinsky but the starting point is often credited to Gerhard Schmidt in connection with photodimerization reactions in crystalline cinnamic acids. Since this initial use, the meaning of the term has broadened considerably to include many aspects of solid state supramolecular chemistry. A useful modern definition is that provided by Gautam Radhakrishna Desiraju, Gaut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermolecular Force
An intermolecular force (IMF) (or secondary force) is the force that mediates interaction between molecules, including the electromagnetic forces of attraction or repulsion which act between atoms and other types of neighbouring particles, e.g. atoms or ions. Intermolecular forces are weak relative to intramolecular forces – the forces which hold a molecule together. For example, the covalent bond, involving sharing electron pairs between atoms, is much stronger than the forces present between neighboring molecules. Both sets of forces are essential parts of force fields frequently used in molecular mechanics. The investigation of intermolecular forces starts from macroscopic observations which indicate the existence and action of forces at a molecular level. These observations include non-ideal-gas thermodynamic behavior reflected by virial coefficients, vapor pressure, viscosity, superficial tension, and absorption data. The first reference to the nature of microscopic forc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Five Component Crystal
5 is a number, numeral, and glyph. 5, five or number 5 may also refer to: * AD 5, the fifth year of the AD era * 5 BC, the fifth year before the AD era Literature * ''5'' (visual novel), a 2008 visual novel by Ram * ''5'' (comics), an award-winning comics anthology * ''No. 5'' (manga), a Japanese manga by Taiyō Matsumoto * The Famous Five (novel series), a series of children's adventure novels written by English author Enid Blyton Films * ''Five'' (1951 film), a post-apocalyptic film * ''Five'' (2003 film), an Iranian documentary by Abbas Kiarostami * ''Five'' (2011 film), a comedy-drama television film * ''Five'' (2016 film), a French comedy film * Number 5, the protagonist in the film ''Short Circuit'' (1986 film) Television and radio * 5 (TV channel), a television network in the Philippines (currently known as TV5 from 2008 to 2018 and again since 2020), owned by TV5 Network, Inc. * Channel 5 (British TV channel), British free-to-air television network sometime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Properties
A materials property is an intensive property of a material, i.e., a physical property that does not depend on the amount of the material. These quantitative properties may be used as a metric by which the benefits of one material versus another can be compared, thereby aiding in materials selection. A property may be a constant or may be a function of one or more independent variables, such as temperature. Materials properties often vary to some degree according to the direction in the material in which they are measured, a condition referred to as anisotropy. Materials properties that relate to different physical phenomena often behave linearly (or approximately so) in a given operating range. Modeling them as linear functions can significantly simplify the differential constitutive equations that are used to describe the property. Equations describing relevant materials properties are often used to predict the attributes of a system. The properties are measured by standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complexity And Scale Of Structures Within Crystalline Materials
Complexity characterises the behaviour of a system or model whose components interact in multiple ways and follow local rules, leading to nonlinearity, randomness, collective dynamics, hierarchy, and emergence. The term is generally used to characterize something with many parts where those parts interact with each other in multiple ways, culminating in a higher order of emergence greater than the sum of its parts. The study of these complex linkages at various scales is the main goal of complex systems theory. The intuitive criterion of complexity can be formulated as follows: a system would be more complex if more parts could be distinguished, and if more connections between them existed. Science takes a number of approaches to characterizing complexity; Zayed ''et al.'' reflect many of these. Neil Johnson states that "even among scientists, there is no unique definition of complexity – and the scientific notion has traditionally been conveyed using particular examples... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Properties Of Crystalline Materials
Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations of arithmetic * Mechanical energy, the sum of potential energy and kinetic energy * Mechanical system, a system that manages the power of forces and movements to accomplish a task * Mechanism (engineering), a portion of a mechanical device Other * Mechanical (character), one of several characters in Shakespeare's ''A Midsummer Night's Dream'' * A kind of typeface in the VOX-ATypI classification See also * Machine, especially in opposition to an electronic item * ''Mechanical Animals'', the third full-length studio release by Marilyn Manson * Manufactured or artificial, especially in opposition to a biological or natural component * Automation, using machine decisions and processing instead of human * Mechanization, using machine labor inste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LRM Photodimer , a conceptual entity–relationship model
{{Disambiguation ...
LRM may refer to: * Land Reform Museum, a museum in Taipei, Taiwan * , a French centrist political party * La Romana International Airport (IATA code), in the Dominican Republic * Learning relationship management, a family of learning management software * Left-to-right mark, a Unicode bidirectional formatting character * LR&M Constructions, an Australian civil engineering and construction company * IFLA Library Reference Model The IFLA Library Reference Model (IFLA LRM) is a conceptual entity–relationship model developed by the International Federation of Library Associations and Institutions (IFLA) that expresses the "logical structure of bibliographic information". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge Crystallographic Data Centre
The Cambridge Crystallographic Data Centre (CCDC) is a non-profit organisation based in Cambridge, England. Its primary activity is the compilation and maintenance of the Cambridge Structural Database, a database of small molecule crystal structures. They also perform analysis on the database for the benefit of the scientific community, and write and distribute computer software to allow others to do the same. History In 1962, Dr. Olga Kennard OBE FRS set up a chemical crystallography group within the Department of Chemistry, University of Cambridge. In 1965 she founded the CCDC and established the associated Cambridge Structural Database. At that time, there were only about 3,000 published X-ray structures, and the work involved converting these into a machine-readable form. In 1992, the CCDC moved into its own building adjacent to the Cambridge chemistry department. This new headquarters was designed by the Danish architect Professor Erik Christian Sørensen and won ''The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure Prediction
Crystal structure prediction (CSP) is the calculation of the crystal structures of solids from first principles. Reliable methods of predicting the crystal structure of a compound, based only on its composition, has been a goal of the physical sciences since the 1950s. Computational methods employed include simulated annealing, evolutionary algorithms, distributed multipole analysis, random sampling, basin-hopping, data mining, density functional theory and molecular mechanics. History The crystal structures of simple ionic solids have long been rationalised in terms of Pauling's rules, first set out in 1929 by Linus Pauling. For metals and semiconductors one has different rules involving valence electron concentration. However, prediction and rationalization are rather different things. Most commonly, the term crystal structure prediction means a search for the minimum-energy arrangement of its constituent atoms (or, for molecular crystals, of its molecules) in space. The problem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetics And Thermodynamics
Kinetics ( grc, κίνησις, , kinesis, ''movement'' or ''to move'') may refer to: Science and medicine * Kinetics (physics), the study of motion and its causes ** Rigid body kinetics, the study of the motion of rigid bodies * Chemical kinetics, the study of chemical reaction rates **Enzyme kinetics, the study of biochemical reaction rates catalysed by an enzyme *** Michaelis–Menten kinetics, the widely accepted general model of enzyme kinetics *** Goldbeter–Koshland kinetics, describe a steady-state solution for a 2-state biological system *** Langmuir–Hinshelwood kinetics **Receptor–ligand kinetics, a branch of chemical kinetics in which the kinetic species are defined by different non-covalent bindings and/or conformations of the molecules involved, which are denoted as ''receptor(s)'' and ''ligand(s)'' *** Hill kinetics *Pharmacokinetics, the study of the processes a substance undergoes in the animal body, particularly the rates at which it is absorbed, distrib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphism (materials Science)
In materials science, polymorphism describes the existence of a solid material in more than one form or crystal structure. Polymorphism is a form of isomerism. Any crystalline material can exhibit the phenomenon. Allotropy refers to polymorphism for chemical elements. Polymorphism is of practical relevance to pharmaceuticals, agrochemicals, pigments, dyestuffs, foods, and explosives. According to IUPAC, a polymorphic transition is "A reversible transition of a solid crystalline phase at a certain temperature and pressure (the inversion point) to another phase of the same chemical composition with a different crystal structure." According to McCrone, polymorphs are "different in crystal structure but identical in the liquid or vapor states." Materials with two polymorphs are called dimorphic, with three polymorphs, trimorphic, etc. Examples Many compounds exhibit polymorphism. It has been claimed that "every compound has different polymorphic forms, and that, in general, the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scanning Probe Microscopy
Scan may refer to: Acronyms * Schedules for Clinical Assessment in Neuropsychiatry (SCAN), a psychiatric diagnostic tool developed by WHO * Shared Check Authorization Network (SCAN), a database of bad check writers and collection agency for bad checks * Space Communications and Navigation Program (SCaN) * Social Cognitive and Affective Neuroscience (journal) * Scientific content analysis (SCAN), also known as statement analysis Businesses * Scan Furniture, Washington, D.C., US chain * SCAN Health Plan, not-for-profit health care company based in Long Beach, California * Scan AB or Scan Foods UK Ltd, the Swedish and UK subsidiaries of the Finnish HKScan Oyj * Seattle Community Access Network, Seattle, Washington, US TV channel * Scan (company), a software company based in Provo, Utah, US Electronics or computer related * 3D scanning * Counter-scanning, in physical micro and nanotopography measuring instruments like scanning probe microscope * Elevator algorithm (also SC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Self-assembly
In chemistry and materials science, molecular self-assembly is the process by which molecules adopt a defined arrangement without guidance or management from an outside source. There are two types of self-assembly: intramolecular and intermolecular. Commonly, the term ''molecular self-assembly'' refers to the former, while the latter is more commonly called ''folding''. Supramolecular systems Molecular self-assembly is a key concept in supramolecular chemistry. This is because assembly of molecules in such systems is directed through non-covalent interactions (e.g., hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, pi-stacking interactions, and/or electrostatic) as well as electromagnetic interactions. Common examples include the formation of colloids, biomolecular condensates, micelles, vesicles, liquid crystal phases, and Langmuir monolayers by surfactant molecules. Further examples of supramolecular assemblies demonstrate that a variety of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
