Single-point interactions

Noncovalently Functionalized Dendrimers Based on Single Point Interactions... 

Fig. 3.2. A schematic representation of the molecular imprinting pre-arrangement phase (corresponding to 2 in Fig. 3.1), here using ()-nicotine as the template and carboxylic acid containing functional monomers. In this case a total of five states of complexation are proposed I, non-complexed template II, weak single point interaction III, strong single point interaction IV, combination of weak and strong interactions V, higher order complexes e.g. monomer interactions with template-template self-association complexes, higher monomer solvation levels.

Ortho substituted heterocyclic bases behave, on a silica surface, like monofunctional solutes and, in most cases, have slopes near unity [for example 2-acetylpyridine, l-(pyridyl-2 )-ethan-l-ol], whereas the slope values for analogous para isomers are much higher. Also, 8-substituted derivatives of quinoline behave like ortho isomers (see 8-hydroxyquinoline). This is caused by the ortho effect— H-bond interactions of two neighboring polar groups (internally H-bonded groups), which cause their weaker adsorption and single-point interactions with surface sila-nols [compare slopes of 5-hydroxyquinoline and 8-hydroxyquinoline, 2-acetylpyridine and 4-acetylpyridine, l-(pyridyl-2 )-ethan-l-ol and l-(pyridyM )-ethan-l-ol]. ... 

Hydrogen bonds are well understood they are strong, single point interactions with a very well-defined geometry. Whereas in the it interaction there... 

You can use a single point calculation that determines energies for ground and excited states, using configuration interaction, to predict frequencies and intensities of an electronic ultraviolet-visible spectrum. 

A configuration interaction calculation is available only for single points when the reference ground state is obtained from an RHF calculation. 

HyperChem always computes the electronic properties for the molecule as the last step of a geometry optimization or molecular dynamics calculation. However, if you would like to perform a configuration interaction calculation at the optimized geometry, an additional single point calculation is required with the Cl option being turned on. 

A completely different type of property is for example spin-spin coupling constants, which contain interactions of electronic and nuclear spins. One of the operators is a delta function (Fermi-Contact, eq. (10.78)), which measures the quality of the wave function at a single point, the nuclear position. Since Gaussian functions have an incorrect behaviour at the nucleus (zero derivative compared with the cusp displayed by an exponential function), this requires addition of a number of very tight functions (large exponents) in order to predict coupling constants accurately. ... 

We can also use the wave-hke nature of light to describe the behavior of an optical system. If we consider the radiation from a single point in the object, it acts like a wave spreading out in all directions. A portion of this wave interacts with our optical system. The wave can be described mathematically as... 

Protein-protein interactions between heterodimeric protein pairs that form only transient interactions can be detected, y-secre-tase is presenilin-1 (PS1) dependent [51-53]. PS1 is a 467-amino acid, 9-transmembrane domain protein. Over 100 documented single point mutations are known to cause autosomal-dominant familial AD (FAD) [54], in which the ratio of the more fibrilogenic variety of A ft (A/142) to the less fibrilogenic variety (A/140) is increased. Chinese hamster ovary (CHO) cells were stably transfected with human APP and either wild type or mutant PS1 [4, 55]. 

The phase space for three-dimensional motion of a single particle is defined in terms of three cartesian position coordinates and the three conjugate momentum coordinates. A point in this six-dimensional space defines the instantaneous position and momentum and hence the state of the particle. An elemental hypothetical volume in six-dimensional phase space dpxd Pydpzdqxdqydqz, is called an element, in units of (joule-sec)3. For a system of N such particles, the instantaneous states of all the particles, and hence the state of the system of particles, can be represented by N points in the six-dimensional space. This so-called /r-space, provides a convenient description of a particle system with weak interaction. If the particles of a system are all distinguishable it is possible to construct a 6,/V-dimensional phase space (3N position coordinates and 3N conjugate momenta). This type of phase space is called a E-space. A single point in this space defines the instantaneous state of the system of particles. For / degrees of freedom there are 2/ coordinates in /i-space and 2Nf coordinates in the T space. 

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