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Dimension classical definition

This is the classical definition of the adjacency matrix, which refers to a simple graph, where multiple bonds are not accounted for. The adjacency matrix is symmetric with dimension Ax A, where A is the number of atoms and it is usually derived from a H-depleted molecular graph. [Pg.2]

Most of the common nanomaterials can be classified in terms of dimensionality, according to the number of orthogonal directions X, Y, Z in which the structural patterns referred to above have dimensions Lx,y,z smaller than the nanoscopic limit Lq. This leads to the classical definitions of dimensionality summarized in Table 5.3-1. However, it should be noted that experimental situations... [Pg.1033]

In classical mechanics, every particle follows a definite trajectory, which specifies its position as a function of time. For the moment, we consider a particle moving in one dimension only. We take this as the x direction, so that the trajectory is a function x(t). The velocity of the particle is the differential of position with respect to time, and the acceleration as the differential of the velocity ... [Pg.17]

As for the QM/MM description also for PCM, non-electrostatic (or van der Walls) terms can be added to the Vent operator in this case, besides the dispersion and repulsion terms, a new term has to be considered, namely the energy required to build a cavity of the proper shape and dimension in the continuum dielectric. This further continuum-specific term is generally indicated as cavitation. Generally all the non-electrostatic terms are expressed using empirical expressions and thus their effect is only on the energy and not on the solute wave function. As a matter of fact, dispersion and repulsion effects can be (and have been) described at a PCM-QM level and included in the solute-effective Hamiltonian 7/eff as two new operators modifying the SCRF scheme. Their definition can be found in Ref. [17] while a recent systematic comparison of these contributions determined either using the QM or the classical methods is reported in Ref. [18]... [Pg.6]

The rationale of using hybrid simulation here is that a classic diffusion-adsorption type of model, Eq. (2), can efficiently handle large distances between steps by a finite difference coarse discretization in space. As often happens in hybrid simulations, an explicit, forward discretization in time was employed. On the other hand, KMC can properly handle thermal fluctuations at the steps, i.e., provide suitable boundary conditions to the continuum model. Initial simulations were done in (1 + 1) dimensions [a pseudo-2D KMC and a ID version of Eq. (2)] and subsequently extended to (2 + 1) dimensions [a pseudo-3D KMC and a 2D version of Eq. (2)] (Schulze, 2004 Schulze et al., 2003). Again, the term pseudo is used as above to imply the SOS approximation. Speedup up to a factor of 5 was reported in comparison with KMC (Schulze, 2004), which while important, is not as dramatic, at least for the conditions studied. As pointed out by Schulze, one would expect improved speedup, as the separation between steps increases while the KMC region remains relatively fixed in size. At the same time, implementation is definitely complex because it involves swapping a microscopic KMC cell with continuum model cells as the steps move on the surface of a growing film. [Pg.22]

The main effect is already taken into account if symmetry numbers are included in the densities of states. The symmetry number is a correction to the density of states that allows for the fact that indistinguishable atoms occupy symmetry-related positions and these atoms have to obey the constraints of the Pauli principle (i.e. the wave function must have a definite symmetry with respect to any permutation), whereas the classical density of states contains no such constraint. The density of states is reduced by a factor that is equal to the dimension of the rotational subgroup of the molecule. When a molecule is distorted, its symmetry is reduced, and so its symmetry number changes by a proportion that is equivalent to the number of indistinguishable ways in which the distortion may be produced. For example, the rotational subgroup of the methane molecule is T, whose dimension is 12, whereas the rotational subgroup of a distorted molecule in which one bond is stretched is C3, whose dimension is 3. The ratio of these symmetry numbers, 4, is the number of ways in which the distortion can occur, i.e. the reaction path degeneracy. [Pg.35]

This power law also holds for most fractal sets S, except that d is no longer an integer. By analogy with the classical case, we interpret d as a dimension, usually called the capacity or box dimension of, S. An equivalent definition is... [Pg.409]

In this introduction it may be useful to give a brief definition of surface tension and surface free energy. The dimension of the surface tension is related to unit length. Lenard s classical experiment (1924) is one of the best demonstrations of the surface force of a liquid acting on an extended wire in contact with a liquid surface. By carefully lifting the wire from the level of the surface, a force can be measured for as long as the pendent lamella remains in contact with the liquid bulk. The force measured in this way, divided by the length of the wire, leads to a well-... [Pg.2]

It should be noted that many refer to flexible thin films (commonly elastomers) as membranes, regardless of their dimensions, presumably because they are easily deformed by relatively low pressures (relative to atmospheric pressure). Here, we adopt the classical mechanics definition of membrane, that is, a stretch-dominated structure (as opposed to bending-dominated). [Pg.1126]

Mandelbrot beUeved initially that one would do better without a precise definition of fractals. His original essay [1] contains none. By 1977, however, he saw the need to produce at least a tentative definition. It is the now classical statement that a fractal is a set for which the Hausdorff dimension strictly exceeds the topological dimension [4, 5,10]. For example, the Cantor set is a fractal, according to this viewpoint, since Dh = 0.631 > Z)r=0. [Pg.42]

Of course it is possible to assimilate the moral dimension into the dimension of self-interest by arguing that in cases such as the above it is in an individual s interest to avoid moral condemnation. But this is far from the spirit of the neo-classical paradigm. Moreover, to argue that it is in people s interest to act morally in order to satisfy their own consciences and win the approval of others expands the concept of self-interest to the point where it has no meaning. On this expanded definition, no matter what a person does, be it moral or immoral, selfish or altruistic, it can be said to be motivated by self-interest. Most importantly, in the present context, to expand the concept in this way is to obliterate the distinction between the market and regulatory approaches to public policy which is the very question at issue in this book. In short, to be able to talk sensibly about policy in this area requires that we maintain this distinction between moral and economic motivation. [Pg.23]


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Dimension, definition

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