Results 351 to 360 of about 12,874,811 (378)

The density in density functional theory

Journal of Molecular Structure: THEOCHEM, 2010
Abstract The paper begins with the definition of the electron density given by Schrodinger in 1926 and traces its use and many applications directed at the understanding of the properties of matter to its present day role in density functional theory and the development of the quantum mechanics of an open system.
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Improved Density Processing for LWD Density

Proceedings of SPE Annual Technical Conference and Exhibition, 2006
Abstract Density measurements are intrinsically sensitive to standoff. In wireline logging, it is possible to have the detectors on a pad, reduce the standoff to a minimum, and correct for other effects with a high-level of accuracy. Logging while drilling (LWD) is more challenging because the standoff is much more important than with ...
John Crowe, Olivier Desport
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Correction of flux measurements for density effects due to heat and water vapour transfer

, 1980
When the atmospheric turbulent flux of a minor constituent such as CO2 (or of water vapour as a special case) is measured by either the eddy covariance or the mean gradient technique, account may need to be taken of variations of the constituent's ...
E. K. Webb, G. Pearman, R. Leuning
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The capacity of low-density parity-check codes under message-passing decoding

IEEE Transactions on Information Theory, 2001
We present a general method for determining the capacity of low-density parity-check (LDPC) codes under message-passing decoding when used over any binary-input memoryless channel with discrete or continuous output alphabets.
T. Richardson, R. Urbanke
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Density and Density Matrices in Density Functional Theory

1990
Publisher Summary This chapter discusses density and density matrices in density functional theory. It also discusses particle number and order; fundamental Hilbert spaces; matrices and restricted operators; local and nonlocal operators; equidensity orbitals and n representability; and negative consequences of a finite model.
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Density functions and density functionals

Philosophical Magazine B, 1994
Abstract This paper is concerned with the electron density and other ‘property densities’ and, through the use of concrete examples, touches upon some of the fundamental aspects of density functional theory (DFT) that are seldom considered. In particular, this paper considers what density functions are needed in discussing observable electronic ...
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Density Matrices and Density Operators

1996
As was repeatedly seen in the last chapter, for computing most of the usual matrix elements only a few of the many coordinates of an N-particle wavefunction are used, where due to the symmetry properties it is irrelevant which ones. Density matrices are a tool to extract the relevant information out of such monstrous constructs as are N-particle ...
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Density Operator, Density Matrix

2011
The density matrix is especially suited for a description of an arbitrary (pure or mixed) polarization state (differently from a wave function). With it averages and expectation values as well as statistical distributions of measurable quantities can be described.
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The postsynaptic density

Current Opinion in Neurobiology, 1993
The postsynaptic density is a specialization of the nerve cell's submembrane cytoskeleton that is hypothesized to participate in the regulation of synaptic adhesion, transmitter receptor clustering, and modulation of receptor sensitivity. Until recently, many of the major proteins in the highly insoluble postsynaptic density fraction remained ...
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Semiempirical GGA‐type density functional constructed with a long‐range dispersion correction

Journal of Computational Chemistry, 2006
S. Grimme
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