Digital computer data structures

Number of data points (NP) is a number adjusted to the memory structure of digital computers, expressed as a power of 2, such as 212 = 4096 or 4K. 

The significant structures theory as developed for liquids by Eyring, Ree, and collaborators is shown to be applicable also to the plastic crystal state. The properties of CBr (in the plastic crystal state) were calculated and compared with the experimental data. The calculations were performed on a digital computer using, without alteration, a program developed for the liquid state. 

The mass spectrometrist sees the digital computer in quite a difEerent light from the theoretical chemist. In mass spectrometry the computer is not generally used to carry out approximations by numerical techniques which vary the parameters. It is mainly cast in the role of mechanical controller, data acquirer and processer, file searcher and as resolver of structures from mass spectra of unknown compounds. 

Data structures are places to put useful things inside a computer. The choice of one kind rather than another is a process of arranging key information to enable its use for some purpose. Another way to define data structures is as practical ways to implement computation on digital computers, taking account of characteristics of the hardware, operating system, and programming language. 

The distance of each reflection from the center of the pattern is a function of the fiber-to-film distance, as well as the unit-cell dimensions. Therefore, by measuring the positions of the reflections, it is possible to determine the unit-cell dimensions and, subsequently, index (or assign Miller indices to) all the reflections. Their intensities are measured with a microdensitometer or digitized with a scanner and then processed.8-10 After applying appropriate geometrical corrections for Lorentz and polarization effects, the observed structure amplitudes are computed. This experimental X-ray data set is crucial for the determination and refinement of molecular and packing models, and also for the adjudication of alternatives. 

It is also possible to digitally record or compute the data required for a diffracting structure and then uses this data to produce relief holograms, usually via a photolithographic process. 

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