Neighboring concept

The Morgan Algorithm classifies all the congeneric atoms of a compound and selects invariant-labeled atoms (see Section 2.5.3.1). The classification uses the concept of considering the number of neighbors of an atom (connectivity), and does so in an iterative manner (extended connectivity, EC). On the basis of certain rules. 

The most striking feature of the earth, and one lacking from the neighboring planets, is the extensive hydrosphere. Water is the solvent and transport medium, participant, and catalyst in nearly all chemical reactions occurring in the environment. It is a necessary condition for life and represents a necessary resource for humans. It is an extraordinarily complex substance. Stmctural models of Hquid water depend on concepts of the electronic stmcture of the water molecule and the stmcture of ice. Hydrogen bonding between H2O molecules has an effect on almost every physical property of Hquid water. 

The basic concepts of shock and particle velocities are well illustrated by an example first introduced by Duvall and Band (1968). Here we assume that a string of beads of diameter d, mass m, and spaced a fixed distance / apart on a smooth (frictionless) wire is impacted by a rigid, massive piston at velocity v. Each bead is assumed to undergo perfectly elastic, rigid-body motion upon impact with its neighbor. 

Let us comment on the developed schematic Monte Carlo (MC) code. Of course there are many clever ways to improve the execution speed. There is the important concept of neighbor lists, of clever implementation of numerical instructions, and so on. In developing a computer simulation one usually plugs in these enhancing concepts bit by bit. 

Supramolecular chemistry is a central theme not only in chemistry, but in neighboring disciplines as well. The author, who has been awarded the Nobel Prize for his achievements in this area, describes the concepts, lines of development and perspectives of this highly interdisciplinary and burgeoning field of research. 

Reactions in solution proceed in a similar manner, by elementary steps, to those in the gas phase. Many of the concepts, such as reaction coordinates and energy barriers, are the same. The two theories for elementary reactions have also been extended to liquid-phase reactions. The TST naturally extends to the liquid phase, since the transition state is treated as a thermodynamic entity. Features not present in gas-phase reactions, such as solvent effects and activity coefficients of ionic species in polar media, are treated as for stable species. Molecules in a liquid are in an almost constant state of collision so that the collision-based rate theories require modification to be used quantitatively. The energy distributions in the jostling motion in a liquid are similar to those in gas-phase collisions, but any reaction trajectory is modified by interaction with neighboring molecules. Furthermore, the frequency with which reaction partners approach each other is governed by diffusion rather than by random collisions, and, once together, multiple encounters between a reactant pair occur in this molecular traffic jam. This can modify the rate constants for individual reaction steps significantly. Thus, several aspects of reaction in a condensed phase differ from those in the gas phase ... 

The basic concept behind all models of chiral self-assembly can be stated as follows. In general, chiral molecules do not pack parallel to their neighbors but rather pack at a slight angle with respect to their neighbors. This favored packing can be visualized by the packing of hard screws,6 as illustrated in... 

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