ISSN:
0192-8651
Keywords:
Computational Chemistry and Molecular Modeling
;
Biochemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Computer Science
Notes:
Dimensionless ratios of various moments of conformation-dependent physical properties play an important role in the evaluation of the behavior of chain molecules. For example, the correlation coefficient, ρxy, between two conformation-dependent physical properties, denoted here as x and y, is determined by the three dimensionless ratios 〈x2〉/〈x〉2, 〈y2〉/〈y〉2, and 〈xy〉/〈x〉〈y〉. Angle brackets denote the statistical mechanical average of the enclosed property. In the rotational isomeric state approximation, generator matrices of modest size can often be used for calculation of 〈x〉 and 〈y〉. The dimensions of the matrices grow rapidly upon going to higher moments or to mixed moments, such as 〈xy〉. Formulation of these large matrices, while straight-forward, has been extremely tedious for chains with independent bonds, arbitrary rotational potentials, and arbitrary bond angles (which need not be fixed). Here we describe an approach that quickly and accurately solves this problem for all cases in which the generator matrices required for 〈x〉 and 〈y〉 are known. The algorithm is validitated by successful use for the computation of ρr2s2 for r2 and s2 for freely jointed chains of various n, a case for which an exact analytical result in closed form is available in the literature. Here r2 and s2 denote the squared end-to-end distance and squared radius of gyration for a specified conformation, and n denotes the number of bonds.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcc.540110314
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