Program description, computer

The statistical perturbation theory arising from the classical work of Zwanzig34 and its detailed implementation in a molecular dynamics program for computation of free energies is described in detail elsewhere.35 36 We give a very brief description of the method for the sake of completeness. The total Hamiltonian of a system may be written as the sum of the Hamiltonian (Ho) of the unperturbed system and the perturbation (Hi) ... 

Campagne, F., Jestin, R., Reversat, J. L Bemassau, J. M and Maigret, B. (1999) Visualisation and integration of G protein-coupled receptor related information help the modelling description and applications of the Viseur program. J. Comput, Aided Mol. Des. 13, 625-643. 

In excerpt 3Y, the authors refer to computational results performed with the Gaussian suite of programs, a computational package used to calculate molecular ab initio or semiempirical electronic structure theory. Computational parameters (e.g., the basis set and level of theory) are included in the description. Do not worry if you do not understand the content of excerpt 3Y the language is intended for chemists with a computational or theoretical background. 

McBride, B J. and Gordon, S. Computer program for calculation of complex chemical equilibrium compositions and apphcations II. User s manual and program description. 2006. http //www.grc.nasa. gov/www/ceaweb/rp-131 l-p2.pdf (accessed September 16, 2009). 

McBride, B.J. and Gordon, S., Computer Program for the Calculation of Complex Chemical Equilibrium Compositions and Applications. 11 — Users Manual and Program Description, NASA RP-1311, 1996. 

Appendix B Brief Descriptions of Computer Programs and Computer Aids for Use with This Book 931... 

The development of a mathematical model begins with an hypothesis that describes the system. The hypothesis is usually expressed as a set of differential equations that can be solved by a computer program. The computer implementation of the model provides not only a description of the system, but also predicts the response of the system to changing conditions. These predictions can be compared to real-world behavior. Since it will always be the case that the model is less complex than the real system, our comparisons will most often lead us to refine the model by increasing its complexity. The principles of formulating and testing mathematical models have been described by Berman (1963). 

Components on the list are usually separated into basis and secondary. Often are included 30-80 or more basis polar, gas and nonpolar organic components of solutions plus a collection of minerals, from which the user may select necessary for the description of composition for all compounds of water, gas and minerals in the study object. Data for the components and minerals include their major properties charge, ionic radius, molecular mass, elemental composition, etc. If an element, for instance strontium (Sr +), is not included among the basis compounds, the program cannot compute the content of its migration forms or minerals even if strontium is present among the initial data. 

Program Description. In order to determine polymer crystal structures, each of the participating Institutions uses computer programs that reflect different resources and abilities as well as philosophies. Models to be used for calculation of Intensities are constructed In various ways, and each has a different strategy for finding the best result. Each of the methods has some unique abilities and some disadvantages. 

There are a number of programs which compute CIP descriptors from local descriptions of configurations. " To be practically useful, however, an algorithm must, first, implement the CIP rules as completely as possible, second, notify the user when the structure is beyond the scope of the implementation, and, third, indicate whether the application of the CIP rules is not appropriate in the case at hand. We know of no system that would fulfill all these criteria. Even the first two are rarely met. 

Dalby A, J G Nourse, W D Hounshell, A K I Gushurst, D L Grier, B A Leland and J Laufer 1991 Description of Several Chemical Structure File Formats Used by Computer Programs Developei at Molecular Design Limited, journal of Chemical Information and Computer Science 32 244-255. 

Several methods of quantitative description of molecular structure based on the concepts of valence bond theory have been developed. These methods employ orbitals similar to localized valence bond orbitals, but permitting modest delocalization. These orbitals allow many fewer structures to be considered and remove the need for incorporating many ionic structures, in agreement with chemical intuition. To date, these methods have not been as widely applied in organic chemistry as MO calculations. They have, however, been successfully applied to fundamental structural issues. For example, successful quantitative treatments of the structure and energy of benzene and its heterocyclic analogs have been developed. It remains to be seen whether computations based on DFT and modem valence bond theory will come to rival the widely used MO programs in analysis and interpretation of stmcture and reactivity. 

The RMDB consists of two mayor sections computer data storage and retrieval system, and backup microfilm data bank file. The computer data storage and retrieval system is used for die standard reliability and maintainability data listing, special calculations, and searches. This data bank system has been established to facilitate remote terminal access compatible with the GIDEP remote terminal programs. The microfilm data bank file is used for storage and distribution of supplier s documents, failure analysis curves, description of methods used in the collection of the data, and additional background information too extensive to include in the computer data bank. 

The treatment in this chapter has been theoretical. For a brief, dear, and very practical description of computational details for a number of standard problems, [10] is unsurpassed, and [12] can be recommended for programming techniques for automatic computers. For information on ordinary differential equations, the reader should consult [2], and for partial differential equations, [1]. For general methods of reduction to algebraic form as well as methods of solution, see [5], [7], and [8]. 

An important step toward the understanding and theoretical description of microwave conductivity was made between 1989 and 1993, during the doctoral work of G. Schlichthorl, who used silicon wafers in contact with solutions containing different concentrations of ammonium fluoride.9 The analytical formula obtained for potential-dependent, photoin-duced microwave conductivity (PMC) could explain the experimental results. The still puzzling and controversial observation of dammed-up charge carriers in semiconductor surfaces motivated the collaboration with a researcher (L. Elstner) on silicon devices. A sophisticated computation program was used to calculate microwave conductivity from basic transport equations for a Schottky barrier. The experimental curves could be matched and it was confirmed for silicon interfaces that the analytically derived formulas for potential-dependent microwave conductivity were identical with the numerically derived nonsimplified functions within 10%.10... 

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