6.2.1 Use of the Randic Connectivity index

The first numerical matrix, when the connectivity index is employed, is named the edge-Randić matrix and denoted by eR. An example of this matrix obtained from the edge-graphical matrix of T2 is given below. For practical reasons only the upper triangle of the matrix is shown.

eR(T2)=
0
3.31
0
0
0
0
0
0
0
3.83
0
0
0
0
3.31
0
3.68
0
0
3.27
0
 
0
3.64
0
0
0
       
0
3.18
0
0
         
0
0
0
           
0
0
           
0

From this matrix can be derived, for example, the vertex-Randić-Wiener index, obtained by summing the elements of the matrix-triangle.

The second numerical matrix is named the path-Randić matrix and denoted by pR. An example of this matrix obtained from the path-graphical matrix of T2 is given below and again only the upper triangle of the matrix is shown.

pR(T2)=
0
3.31
3.41
3.00
3.00
2.00
2.91
2.77
0
3.83
3.83
3.41
2.41
3.33
3.31
0
3.68
3.27
2.27
3.27
3.41
 
0
3.64
2.64
2.82
3.41
       
0
3.18
2.41
3.00
         
0
1.41
2.00
           
0
2.91
           
0

From this matrix can be obtained, for example, the path-Randić-Wiener index by summing up the elements in the matrix-triangle.

The third numerical matrix is named the sparse vertex-Randić matrix and denoted by svR. An example of this matrix obtained from the sparse vertex-graphical matrix of T2 is given below. Only the upper matrix-triangle is given.

svR(T2)=
0
2.41
0
0
0
0
0
0
0
1.41
0
0
0
0
2.41
0
2.41
0
0
2.83
0
 
0
2.27
0
0
0
       
0
2.64
0
0
         
0
0
0
           
0
0
           
0

The summation of the matrix-elements in the above matrix-triangle gives the sparse vertex-Randić-Wiener index.

The fourth numerical matrix is named the dense vertex-Randić matrix and denoted by dvR. An example of this matrix obtained from the dense vertex-graphical matrix of T2 is given below and again only the upper matrix-triangle is given.

dvR(T2)=
0
2.41
2.41
2.91
2.27
2.81
2.91
2.77
0
1.41
2.00
1.41
1.91
1.91
2.41
0
2.41
1.41
2.41
2.83
2.41
 
0
2.27
2.27
2.41
2.91
       
0
2.64
2.27
2.27
         
0
2.77
2.81
           
0
2.91
           
0

The molecular descriptor based on this matrix, obtained by summing the elements in its triangle, is called the dense vertex-Randić-Wiener index.

<< . . . >>