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Efficiency formula for

In modem quantum chemistry packages, one can obtain molecular basis set at the optimized geometry, in which the wave functions of the molecular basis are expanded in terms of a set of orthogonal Gaussian basis set. Therefore, we need to derive efficient formulas for calculating the above-mentioned matrix elements, between Gaussian functions of the first and second derivatives of the Coulomb potential terms, especially the second derivative term that is not available in quantum chemistry packages. Section IV is devoted to the evaluation of these matrix elements. [Pg.515]

The self-consistent field procedure in Kohn-Sham DFT is very similar to that of the conventional Hartree-Fock method [269]. The main difference is that the functional Exc[p] and matrix elements of Vxc(r) have to be evaluated in Kohn-Sham DFT numerically, whereas the Hartree-Fock method is entirely analytic. Efficient formulas for computing matrix elements of Vxc(r) in finite basis sets have been developed [270, 271], along with accurate numerical integration grids [272-277] and techniques for real-space grid integration [278,279]. [Pg.714]

The expressions for 1-D fin efficiency formulas for some common fins are presented in Table 17.7. For other fin geometries, refer to Refs. 13 and 14. The fin efficiencies for straight (first and third from the top in Table 17.7) and circular (seventh from the top in Table 17.7) fins of uniform thickness 8 are presented in Fig. 17.27 (relr = 1 for the straight fin). [Pg.1278]

T. Momose and T. Shida, J. Chem. Phys., 87,2832 (1987). Efficient Formulas for Molecular Integrals over the Hiller-Sucher-Feinberg Identity Using Cartesian Gaussian Functions. Towards the Improvement of Spin Density Calculations. [Pg.31]

AN EFFICIENT FORMULA FOR COMPUTING ELECTRON DENSITIES AND RELATED PROPERTIES... [Pg.10]

Other formulas for the derivation of screen efficiency are used. Taggart Handbook of Mineral Dressing) gives the formula... [Pg.1775]

It should be noted that to use the above time-domain formulas for computing rates, one would need an efficient means of propagating wave packets on the neutral and anion surfaces, and one, specifically, that would be valid for longer times than are needed in the optical spectroscopy case. Why Because, in the non-BO situation, the product is multiplied by exp(iEtZh) and then integrated over time. In the spectroscopy case, is multiplied by... [Pg.305]

It is important to realize that though the formulas for RME explicitly do not depend on reaction scale, x, since this variable cancels out in the computation, RME does in fact implicitly depend on reaction scale because reaction yields are scale dependent and RME in turn depends on reaction yield. Reaction yields are parameters whose magnitude cannot be predicted theoretically but must be verified experimentally. It does not always follow that a reported yield for a given reaction at a given scale will be the same at another scale. This requires experimental verification. Moreover, the direction of change as the scale is changed is also not predictable. AH of this means that when the same synthesis plan is run at a different scale, different reaction yields will be determined and hence different material efficiency performance values of RME, Em and mass of waste will be obtained. However, the... [Pg.109]

The oligomeric formulas are also known as chemically defined formulas. This class of formulas can be subcategorized based on whether the formula contains all free amino acids (elemental formulas) or peptides (peptide-based) as the protein source. Some of these formulas contain a combination of free amino acids and small peptides. Actually, dipeptides and tripeptides in these formulas are absorbed more efficiently than free amino acids. Oligomeric formulas may be better tolerated than polymeric formulas for patients with defects in GI function and maybe particularly useful in patients with severe pancreatic dysfunction or significantly decreased GI surface area (e.g., short bowel syndrome). [Pg.1517]

Organotin compounds with the general formulae RSnX3, R2SnX2, R3SnX and RSnOOH (R = alkyl or aryl and X = Cl, Br or J) are efficient catalysts for the polymerization of oxiranes 73). [Pg.120]

Over the temperature interval 165 K to 300 K, the calculations of Silinsh and Jurgis (1985) indicate that the thermalization rate in pentacene decreases from 3 X 1012 to 0.8 X 1012 s 1. The trend is opposite to what would be expected in liquid hydrocarbons and may be attributed to the rapid increase of mcff with temperature. The calculated mean thermalization distance increases with incident photon energy fairly rapidly, from 3 nm at 2.3 eV to 10 nm at 2.9 eV, both at 204 K. With increasing temperature, (r) decreases somewhat. These thermalization distances have been found to be consistent with the experimental photogeneration quantum efficiency when Onsager s formula for the escape probability is used. [Pg.278]

Table 14.9 summarizes respective formulae for kq of optimal inhibitors as functions of T, [InH]0,/, and k3. At V = const, the kq value of optimal inhibitor decreases with increasing temperature. But during autoxidation, kq and T change unidirectionally. Such an inconsistency is due to an inverse relation between the efficiency of inhibitor and the temperature dependence of zyo. The temperature-dependent rate constant k3 may also contribute to this inconsistency, with the contribution depending on the ratio k3/( 1 + /)[InH]0. [Pg.510]

From numerous tests involving optimization of nonlinear functions, methods that use derivatives have been demonstrated to be more efficient than those that do not. By replacing analytical derivatives with their finite difference substitutes, you can avoid having to code formulas for derivatives. Procedures that use second-order information are more accurate and require fewer iterations than those that use only first-order information(gradients), but keep in mind that usually the second-order information may be only approximate as it is based not on second derivatives themselves but their finite difference approximations. [Pg.207]

Probabilities Predicted by the Erlang Formula for a Completely Free, and a Completely Occupied Surface at Various Surface Efficiencies. M = 5... [Pg.295]

Finally, FDTD may be used to model the coupling of the focal field into the PhC-waveguide, potentially with the presence of an air or glue gap. Even such a simulation procedure with adapted numerical methods for each part of the propagation requires a considerable computation time. To speed up the simulation process for system optimisation remarkably, the FDTD-simulation can be replaced by a formula for the coupling efficiency to a conventional high-index or a PhC-waveguide, ... [Pg.273]

The purpose of the statistical analysis is to estimate the bias and the precision (measured by the CVp of the total precision error of a subject method) and resolve the latter error into components CVg due to the sampling method (less pump error), due to the analytical method (including error in the desorption efficiency factor), and CVp (an assumed level of pump error). Appendix II gives the definitions and computational formulae for the statistical analysis. [Pg.508]

B.D. Burlutskii, Ibid 1969, (67/24), pp 186-201 CA 73, 16940z(1970) (Industrial efficiency of the expl breakdown of mica-contg rocks in open pit mines of the Aldan mica combine was detd. A new formula for calcn... [Pg.609]

Pd(H) fcrf-butyl peroxidic complexes of the general formula [RCOOPdOOferf-Bu]4 are very efficient reagents for the selective stoichiometric oxidation of terminal alkenes in anhydrous nonbasic organic solvents at ambient temperature.518 They also catalyze the ketonization by tert-BuOOH. Internal olefins are not reactive at all. A peroxometallacycle intermediate (see discussion below) was suggested. [Pg.473]

It is a characteristic of process equipment, that the best operation is reached, at neither a very high nor a very low loading. The intermediate equipment load that results in the most efficient operation is called the the best efficiency point. For distillation trays, the incipient flood point corresponds to the best efficiency point. We have correlated this best efficiency point, for valve and sieve trays, as compared to the measured pressure drops in many chemical plant and refinery distillation towers. We have derived the following formula ... [Pg.14]

Line searches are often used in connection with Hessian update formulas and provide a relatively stable and efficient method for minimizations. However, line searches are not always successful. For example, if the Hessian is indefinite there is no natural way to choose the descent direction. We may then have to revert to steepest descent although this step makes no use of the information provided by the Hessian. It may also be... [Pg.312]


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See also in sourсe #XX -- [ Pg.32 , Pg.34 ]




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Efficiencies for

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