Line shape numerical precision

There are numerous needs for precise atomic data, particularly in the ultraviolet region, in heavy and highly ionized systems. These data include energy levels, wavelengths of electronic transitions, their oscillator strengths and transition probabilities, lifetimes of excited states, line shapes, etc. [278]. 

Figure 7. Reciprocal conductivities, A = 0.10. The computed times and isochrones (heavy lines) were markedly different from the shape of isochrones predicted theoretically by Muler and Markin, 1978 which more closely approximated the box formed by the lighter straight lines at /, / = 10 presumably the discrepancy occurred because they assumed plane-wave current flow patterns. Same format as Figure 5. Note that excitation times are not precisely symmetric between the x, y axes, a discrepancy that must arise from numerical error. Here g/, g y = 0.20, g, g/, = 0 02 mSiemens/mm At 0.01 ms djc, dy = 0.10 mm. [Reproduced from the Biophysical Journal 45 831-850 (1984) by copyright permission of the Biophysical Society].

Besides immediate practical applications in fields such as drug design, molecular surfaces contribute to the transformation of modernizing the conceptual arsenal of chemistry, long dominated by line drawings of chemical bonds of structural formulas. Molecular surfaces have led to a true appreciation of the three-dimensional aspects of molecules, important in all branches of chemistry. Precise methods for the analysis of the shapes of these surfaces are available using the topological shape codes and provide tools for the numerical evaluation of such elusive but important properties as measures of molecular similarity and shape complementarity. 

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