Molecular static method

Key words Impurity exciton, electroabsorption spectra, molecular static method, vibrational density of states, recursion method... 

The lattice relaxation near the impurities was calculated on the basis of the molecular static method. The crystal with the impurity was dividing into regions an inner region 1 and an outer region 2+3 (see Fig. 2). The energy of the static lattice of this system can be written as ... 

Statical Method.—The most convenient form of apparatus for determining molecular weight by this method is Beckmann s boiling-point apparatus shown m Fig. 32. 

Pyroelectricity of several kinds of alternating LB films consisting of phenylpyrazine derivatives and stearic acid was measured by the static method at various temperatures. Effects of thermal expansion and molecular packing density of the film on pyroelectricity were also examined. The following conclusions were derived. 

In contrast to fhe static methods discussed in the previous section, molecular dynamics (MD) includes thermal energies exphcitly. The method is conceptually simple an ensemble of particles represents fhe system simulated and periodic boundary conditions (PBC) are normally apphed to generate an infinite system. The particles are given positions and velocities, fhe latter being assigned in accordance with a... 

Molecular statics calculations by Buldum and Cfraci [71] support the hypothesis that the observed lock-in orientations are directly related to commensurate registry, and the particular set of commensurate orientations is determined by the CNT chirality (the wrapping orientation of the outer graphene sheet of the CNT). Thus the friction experiments provide a novel method for measuring the nanotube chirality. Large multiwall CNTs of different... 

That the alteration in the vapour pressure is a small quantity is at once shown by the ratio v/Y Thus in the case of water at xoo° C, the molecular volume of the liquid may be taken to be 18 c c approximately, and the molecular volume of the vapour as 20,000 c c approximately Hence v/Y = o 0009 approximately This small fraction denotes the increase in the saturated vapour pressure expressed in atmospheres, due to increasing the external pressure by one atmosphere The change is of the order of one part in 1000 and is therefore a negligible quantity It follows, however, that in vapour pressure measurements the static method gives the true value whilst the dynamic or streaming method gives the vapour pressure at an external pressure of one atmosphere The difference between the two values is, however, often undetectable... 

The low rate at which equilibrium between the adsorption layer and the bulk is established is typical for high molecular weight surface active substances for which the surface tension gradually decreases with time. The measurement of the surface tension by static and semi-static methods (see Chapter I, 4) as a function of time during the formation of adsorption layers allows one to retrieve information on the kinetics of adsorption phenomena [11,12]. 

Hamada214 has investigated the static molecular and crystalline susceptibilities ( , x(3)) for polysilanes. The method involves a combination of the CPHF method and the oriented-gas model for the crystal internal fields. The results were used to propose a molecular design method for polysilane based materials. 

Vetrivel, Catlow and Colbourn. A small cluster treated explicitly by ab initio molecular orbital methods was embedded in an 82-ion point ion block chosen so that the Madelung potential and electric field reproduced those from static lattice calculations. The effect of aluminium substitution on the proton binding energy was determined, and found to be stronger than when Al was present in the framework. 

Static quantum mechanical calculations have respectable energetic accuracy but are Hmited to a single geometry per calculation. On the other hand, classical molecular dynamics calculations are able to take into account dynamic effects which might be critical to enzyme catalysis and are difficult to deal with by conventional quantum mechanics these calculations employ empirical force fields, however. The Car-Parrinello molecular dynamics method (CPMD) [41, 42], though, has successfully incorporated the accuracy of quantum mechanical calculations into dynamics simulations at a reasonable cost. CPMD 3.5 [43] has been employed by our group to investigate various model systems related to the ODCase mechanism [44]. 

---