Correlations molecular

Woon D E 1994 Benchmark calculations with correlated molecular wavefunctions. 5. The determination of accurate ab initio intermolecular potentials for He2, Ne2, and A 2 J. Chem. Phys. 100 2838... 

Apply the results. Correlate molecular weight and molecular weight distribution data (M , M , M etc.) with desirable or undesirable properties of polymers. 

Dunning, T. H., 1989, Gaussian Basis Sets for Use in Correlated Molecular Calculations. I. The Atoms Boron Through Neon and Hydrogen , J. Chem. Phys., 90, 1007. 

One of the key parameters for correlating molecular structure and chemical properties with bioavailability has been transcorneal flux or, alternatively, the corneal permeability coefficient. The epithelium has been modeled as a lipid barrier (possibly with a limited number of aqueous pores that, for this physical model, serve as the equivalent of the extracellular space in a more physiological description) and the stroma as an aqueous barrier (Fig. 11). The endothelium is very thin and porous compared with the epithelium [189] and often has been ignored in the analysis, although mathematically it can be included as part of the lipid barrier. Diffusion through bilayer membranes of various structures has been modeled for some time [202] and adapted to ophthalmic applications more recently [203,204]. For a series of molecules of similar size, it was shown that the permeability increases with octa-nol/water distribution (or partition) coefficient until a plateau is reached. Modeling of this type of data has led to the earlier statement that drugs need to be both... 

The density functional theory calculations of primary 14C KIE and secondary deuterium kinetic isotope effects (SKIE)220 did not reproduce satisfactorily all the experimentally determined 14C KIE and deuterium (4,4-2H2)- and 6,6-2H2-SKIE, though the non-local DFT methods provide transition state energies on a par with correlated molecular orbital theory221. 

Before attempting to develop any theory correlating molecular to cholesteric handedness, one must be completely sure of the experimental data. A cholesteric phase is fully described by its handedness and pitch, and often also knowledge of the pitch variations with temperature is fundamental. In particular, the determination of the handedness is quite a delicate matter. Before discussing the methods currently used to determine handedness and pitch, the principal textures of the cholesteric phase must be briefly reviewed The planar or Grandjean textures are obtained in thin cells by rubbing the cell walls (with... 

In this report, we have summarized some attempts to correlate molecular to cholesteric chirality both in thermotropic and lyotropic fields. In the former case, we have described only cholesteric induction, while in the lyotropic field, only cholesterics formed by helical polymers have been dealt with, as chiral micellar systems, for the moment, are too complex. 

Instead of a two-component equation as in the non-relativistic case, for fully relativistic calculations one has to solve a four-component equation. Conceptually, fully relativistic calculations are no more complicated than non-relativistic calculations, hut they are computationally demanding, in particular, for correlated molecular relativistic calculations. Unless taken care of at the outset, spurious solutions can occur in variational four-component relativistic calculations. In practice, this problem is handled by employing kinetically balanced basis sets. The kinetic balance relation is... 

T. H. Dunning, Gaussian basis sets for use in correlated molecular calculations. 1. The atoms boron through neon and hydrogen. J. Chem. Phys. 90, 1007-1023 (1989). 

Pierloot, K., Dumez, B., Widmark, P.-O., Roos, B.O. Density-matrix averaged atomic natural orbital (ANO) basis-sets for correlated molecular wave-functions. IV. Medium-size basis-sets for the atoms H-Kr. Theor. Chim. Acta 1995, 90, 87-114. 

In the present work, we will use a relatively low level of theory to derive 32 weakly correlated molecular descriptors, each based on the subdivision and classification of the molecular surface area according to three fundamental properties contribution to ClogP, molar refractivity, and atomic partial charge. The resulting collection will be shown to have applicability in QSAR, QSPR, and compound classification. Moreover, the derived 32 descriptors linearly encode most of the information of a collection of traditional mathematical descriptors used in QSAR and QSPR. 

A major practical issue affecting MP calculations is caused by use of correlated molecular descriptors. During subsequent MP steps, exact halves of values (and molecules) are only generated if the chosen descriptors are uncorrelated (orthogonal), as shown in Fig. 1A. By contrast, the presence of descriptor correlations (and departure from orthogonal reference space) leads to overpopulated and underpopulated, or even empty, partitions (see also Note 5), as illustrated in Fig. ID. For diversity analysis, compounds should be widely distributed over computed partitions and descriptor correlation effects should therefore be limited as much as possible. However, for other applications, the use of correlated descriptors that produce skewed compound distributions may not be problematic or even favorable (see Note 5). 

The further assumption that 3M is degenerate with the correlating molecular triplet state 3M provides an estimate of the energy (3M ) of this state in the region (XM ) > (3M ) > E(3M ) which may be spectroscopically inaccessible. Double intersystem crossing to different molecular triplet states of naphthalene87 is also apparently exhibited by the excimer of 1,6-dimethylnaphthalene40 in which the nonradiative process is characterized by a rate constant kf which is the sum of temperature-dependent and temperature-independent terms. The value of the latter is also consistent with a spin-prohibited process (Table XVI). 

Blower PE, Yang C, Fligner MA et al. Pharmacogenomic analysis correlating molecular substructure classes with microarray gene expression data. Pharmacogenomics J2002(2-.259-271. 

There is a long history of efforts to find simple and interpretable /i and fi functions for various activities and properties (29, 30). The quest for predictive QSAR models started with Hammett s pioneer work to correlate molecular structures with chemical reactivities (30-32). However, the widespread applications of modern predictive QSAR and QSPR actually started with the seminal work of Hansch and coworkers on pesticides (29, 33, 34) and the developments of various powerful analysis tools, such as PLS (partial least squares) and neural networks, for multivariate analysis have fueled these widespread applications. Nowadays, numerous publications on guidelines, workflows, and... 

Witschi H, Haschek WM. Some problems correlating molecular mechanisms and cell damage. In Bhatnagar RS, ed. Molecular Basis of Environmental Toxicity, Ann Arbor Ann Arbor Science Publications 1980. 

Kinney, C.R. 1938. A system correlating molecular structure of organic compounds with their boiling points. I Aliphatic boiling point numbers. J. Am. Chem. Soc. 60 3032-39. 

D. E. Woon andT. H. Dunningjr.,/. Chem. Phys., 99,1914 (1993). Benchmark Calculations with Correlated Molecular Wave Functions. I. Multireference Configuration Interaction Calculations for the Second Row Diatomic Hydrides. 

The functional pheromone of Ca. hemipterus appears to be a subset of the male-specific hydrocarbons (5-8 in Figure 19.3, Bartelt et al., 1992b). The compounds of Ca. hemipterus that were active had structural features in common as drawn in Figure 19.3, the left-hand portions of the active compounds were identical. Petroski and Vaz (1995) used computer-based molecular modeling to correlate molecular shape with biological activity. 

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