Semi-empirical local form

Such considerations have allowed the development of highly efficient potential energy surface walking algorithms (see, for example, J. Nichols, H. L. Taylor, P. Schmidt, and J. Simons, J. Chem. Phys. 92, 340 (1990) and references therein) designed to trace out streambeds and to locate and characterize, via the local harmonic frequencies, minima and transition states. These algorithms form essential components of most modern ab initio, semi-empirical, and empirical computational chemistry software packages. 

Dolan et al. [ 176] and Rinzler et al. [ 142] presented a semi-empirical approach based on a single configuration coordinate model (see Sect. 3.1) for separating the effects of local compressibihty and crystal field strength on pressure-induced changes in the T2 energy of Cr + in several fluoride elpasohte systems. Their approach is based on an empirical form, motivated by the Born-Mayer potential, for the local compressibility k(P) ... 

Once the physico-chemical basis of secondary structure packing is determined, and once the local interactive forces that give rise to secondary structure are known, it vrill be possible to predict both the folding pathway and the final stable conformation of a protein from its amino-add sequence. There are three approaches to these problems, (a) One can correlate sequence and structure using data from as many proteins as possible and derive empirical probabilities for any particular sequence-forming secondary structure, (b) One can derive semi-empirical energy functions for amino-add sequences based on allowed conformation around the... 

For calculating the minimum stirrer speed necessary to keep a given swarm of solid particles in suspension, a number of semi-empirical correlations have been proposed in literature. They are of two t es either the minimum required Froude number (n dlg) is specified, or the minimum required local energy dissipation e, close to the bottom of the tank, r sufficiently small particles these have the following general form (for d < 10 d) ... 

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