The Szeged Index and an Analogy with the Wiener Index
The Szeged Index and an Analogy with the Wiener Index
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DOI:
10.1021/ci00025a024
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发表时间:
1995-05
期刊:
影响因子:
--
通讯作者:
P. Khadikar;N. Deshpande;P. P. Kale-P.;A. Dobrynin;I. Gutman;G. Dömötör
中科院分区:
文献类型:
--
作者:
P. Khadikar;N. Deshpande;P. P. Kale-P.;A. Dobrynin;I. Gutman;G. Dömötör
One of the oldest and most thoroughly examined molecular-graph-based structural descriptors of organic molecules is the Wiener index or Wiener number, W. 1-7 This quantity is equal to the sum of distances between all pairs of vertices of the respective molecular graph. If d («, v| G) is the distance8 of the vertices u and v of the graph G (ie, the number of edges in the shortest path that connects u and v), and V (G) is the vertex set of G, then n2 (e| G) is the number of vertices closer to v than to u; vertices equidistant to u and v are not counted. The above definition has the advantage of being applicable to an arbitrary edge of an arbitrary graph.(Notice that in our definition it is not required that the graph G is connected; in chemical applications, however, one encounters only connected graphs.) In view of this, it readily comes to mind to examine the right-hand side of (2) for cyclic graphs. This, on the other hand, is tantamount to the introduction of a novel topological index Sz= Sz (G), 10 defined as