entries are complementary to the other crystallographic databases such as the Protein
Data Bank (PDB), Inorganic Crystal Structure Database and the International Centre
for Diffraction Data. Generally the entries are derived from X-ray crystallography,
but it also has data based on electron and neutron diffraction. The other important
databases for small molecules are the Crystallography Open Database and the
Inorganic Crystal Structure Database. The Biological Macromolecular
Crystallisation Database, the Protein Data Bank and the Nucleic Acid Database
provide structural information on systems of biological importance.
A similar database has been developed for powder X-ray diffraction studies. The
organisation was founded in 1941 as the Joint Committee on Powder Diffraction
Standards (JCPDS). The International Centre for Diffraction Data (ICDD) was set
up in 1978 and maintains a database of powder diffraction patterns. The Powder
Diffraction File (PDF) includes the d-spacings and relative intensities of observable
diffraction peaks for the samples. It has been designed to work with a diffractometer
to identify unknown materials. With every entry, the database also contains bibliographic references, chemistry descriptions, structural classifications, crystallographic and physical properties. It also includes data on minerals and organic and
pharmaceutical compounds. The 2019 release contains 893,400 unique data sets
obtained from powder diffraction studies.
7 Related Diffraction Techniques
7.1 Introduction
Major contributions were made to the development of diffractometer and the conversion of the raw diffraction data into a model of the underlying atomic structure in
the crystal, and within 50 years, X-ray crystallography had matured from solving the
structures of simple inorganic salts to the determination of the structures of proteins,
enzymes and nucleic acids (resulting in the development of molecular biology) and
the elucidation of the structures of semiconductors, super-conductors, stereoregular
polymers and new catalysts tor the interconversion of hydrocarbons (resulting in the
subdisciplines of metallurgy and materials science) [5–14]. The discovery that the
diffraction of X-rays could be used to unravel the secrets of crystals prompted
physicists to explore the possibility that other atomic particles could generate
diffraction patterns from inorganic crystals, liquids and gases. The contributions of
Arthur Compton and Louis de Broglie (see Table 1) proved to be particularly
important because they conclusively showed that all atomic particles have wave
and particle properties and thereby completed Planck and Einstein’s earlier work.
Specifically, de Broglie proposed that the wavelength, λ, of an atomic particle with
mass m and velocity v was connected by the following deceptively simple equation:
26
D. M. P. Mingos
Data Bank (PDB), Inorganic Crystal Structure Database and the International Centre
for Diffraction Data. Generally the entries are derived from X-ray crystallography,
but it also has data based on electron and neutron diffraction. The other important
databases for small molecules are the Crystallography Open Database and the
Inorganic Crystal Structure Database. The Biological Macromolecular
Crystallisation Database, the Protein Data Bank and the Nucleic Acid Database
provide structural information on systems of biological importance.
A similar database has been developed for powder X-ray diffraction studies. The
organisation was founded in 1941 as the Joint Committee on Powder Diffraction
Standards (JCPDS). The International Centre for Diffraction Data (ICDD) was set
up in 1978 and maintains a database of powder diffraction patterns. The Powder
Diffraction File (PDF) includes the d-spacings and relative intensities of observable
diffraction peaks for the samples. It has been designed to work with a diffractometer
to identify unknown materials. With every entry, the database also contains bibliographic references, chemistry descriptions, structural classifications, crystallographic and physical properties. It also includes data on minerals and organic and
pharmaceutical compounds. The 2019 release contains 893,400 unique data sets
obtained from powder diffraction studies.
7 Related Diffraction Techniques
7.1 Introduction
Major contributions were made to the development of diffractometer and the conversion of the raw diffraction data into a model of the underlying atomic structure in
the crystal, and within 50 years, X-ray crystallography had matured from solving the
structures of simple inorganic salts to the determination of the structures of proteins,
enzymes and nucleic acids (resulting in the development of molecular biology) and
the elucidation of the structures of semiconductors, super-conductors, stereoregular
polymers and new catalysts tor the interconversion of hydrocarbons (resulting in the
subdisciplines of metallurgy and materials science) [5–14]. The discovery that the
diffraction of X-rays could be used to unravel the secrets of crystals prompted
physicists to explore the possibility that other atomic particles could generate
diffraction patterns from inorganic crystals, liquids and gases. The contributions of
Arthur Compton and Louis de Broglie (see Table 1) proved to be particularly
important because they conclusively showed that all atomic particles have wave
and particle properties and thereby completed Planck and Einstein’s earlier work.
Specifically, de Broglie proposed that the wavelength, λ, of an atomic particle with
mass m and velocity v was connected by the following deceptively simple equation:
26
D. M. P. Mingos