# Computing the Entropy Measures for the Line Graphs of Some Chemical Networks

Authors: Muhammad Farhan Hanif; Hasan Mahmood; Shazia Manzoor; Fikre Bogale Petros
Journal: Computational Intelligence and Neuroscience
 (2022)

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## Abstract

Chemical Graph entropy plays a significant role to measure the complexity of chemical structures. It has explicit chemical uses in chemistry, biology, and information sciences. A molecular structure of a compound consists of many atoms. Especially, the hydrocarbons is a chemical compound that consists of carbon and hydrogen atoms. In this article, we discussed the concept of subdivision of chemical graphs and their corresponding line chemical graphs. More preciously, we discuss the properties of chemical graph entropies and then constructed the chemical structures namely triangular benzenoid, hexagonal parallelogram, and zigzag edge coronoid fused with starphene. Also, we estimated the degree-based entropies with the help of line graphs of the subdivision of above mentioned chemical graphs.


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## Body

## 1. Introduction

Mathematical chemistry is a field of theoretical chemistry that uses mathematical approaches to discuss molecular structure without necessarily referring to quantum mechanics [1]. Chemical Graph Theory is a branch of mathematical chemistry where a chemical phenomenon is theoretically described using graph theory [2, 3]. The growth of organic disciplines has been aided by Chemical Graph Theory [4, 5]. In mathematical chemistry, graph invariants or topological indices are numeric quantities that describe various essential features of organic components and are produced from an analogous molecular graph [6, 7]. Degree-based indices are among the topological indices used to predict bioactivity, boiling point, draining energy, stability, and physico-chemical properties of certain chemical compounds [8, 9]. Due to their chemical applications, these indices have significant role in theoretical chemistry. Zhang et al. [10–12] discuss the topological indices of generalized bridge molecular graphs, Carbon Nanotubes and product of chemical graphs. Zhang et al. [13–15] provided the physical analysis of heat for formation and entropy of Ceria Oxide. For further study about indices, see [16, 17].Shannon [18] originated the conception of information entropy in communication theory. However, it was later discovered as a quantity that applied to all things with a set nature [19, 20], including molecular graphs [21–23]. In chemistry, information entropy is now used in two modes. Firstly, it is a structural descriptor for assessing the complexity of chemical structures [24]. Information entropy is useful in this regard for connecting structural and physico-chemical features [25], numerically distinguishing isomers of organic molecules [26], and classifying natural products and synthetic chemicals [27, 28]. The physico-chemical sounding of information entropy is a different mode of application. As a result, Terenteva and Kobozev demonstrated its utility in analyzing physico-chemical processes that simulate information transmission [29]. Zhdanov [30] used entropy values to study organic compound chemical processes. The information entropy is defined as:(1)ENTψF=−∑i=1qNiΛlimiInlogΛlimiIn,=logIn−1In∑i=1qNiΛlimilogΛlimi.Here, the logarithm is considered to be with base e while FV , FE and Λlm represent the vertex set, the edge set and the edge weight of the edge lm in Λ. Many graph entropies have been calculated in the literature utilising characteristic polynomials, vertices degree, and graph order [31–34]. Graph entropies, which are based on independent sets, matchings, and the degree of vertices [35], have been estimated in recent years. Dehmer and Mowshowits proposed several graph complexity and Hosoya entropy relationships [23, 32, 36, 37]. For further study, see [19, 21, 38–42, 59, 60].The graph F is structured into ordered pairs, with one object being referred to as a vertex set FV and the other as an edge set FE, and these vertices and edges being connected. When two vertices of F share an edge, they are said to be neighboring. The sum of the degrees of all neighboring vertices of l is denoted by Al, and the degree of a vertex l is represented by ℵ∧l. By replacing each of SF’s edges with a path of length two, the subdivision graph SF is formed. The line graph is denoted by the symbol LF in which VLF=EF and two vertices of LF are adjacent iff their corresponding edges share a common end points in F.


### 1.1. Randić Entropy [43, 44]

IfΛlm=ℵ∧l×ℵ∧mα,withα=1,−1,1/2,−1/2, then(2)∑lm∈FEΛlm=∑lm∈FEℵ∧l×ℵ∧mα=Rα.Now (1) represent the Randic′ Entropy.(3)ENTRαF=logRα−1Rα∑i=1q∑lm∈FEiℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα.


### 1.2. Atom Bond Connectivity Entropy [45]

IfΛlm=ℵ∧l×ℵ∧m−2/ℵ∧l×ℵ∧m, then(4)∑lm∈FEΛlm=∑lm∈FEℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=ABCF.Thus (1) is converted in the following form:(5)ENTABCF=logABC−1ABC∑i=1q∑lm∈FEiℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m.


### 1.3. The Geometric Arithmetic Entropy [43, 44]

IfΛlm=2ℵ∧l×ℵ∧m/ℵ∧l+ℵ∧m, then(6)∑lm∈FEΛlm=∑lm∈FE2ℵ∧l×ℵ∧mℵ∧l+ℵ∧m=GAF.Now (1) takes the form as given below.(7)ENTGAF=logGA−1GA∑i=1q∑lm∈FEi2ℵ∧l×ℵ∧mℵ∧l+ℵ∧mlog2ℵ∧l×ℵ∧mℵ∧l+ℵ∧m.


### 1.4. The Fourth Atom Bond Connectivity Entropy [35]

IfΛlm=Al+Am−2/AlAm, then(8)∑lm∈EFΛlm=∑lm∈EFAl+Am−2AlAm=ABC4F.Now (1) converted in the following form as:(9)ENTABC4F=logABC4F−1ABC4F∑i=1q∑lm∈EiFlogAl+Am−2AlAmAl+Am−2/AlAm.


### 1.5. The Fifth Geometric Arithmetic Entropy [35]

IfΛlm=2AlAm/Al+Am, then(10)∑lm∈EFΛlm=∑lm∈EF2AlAmAl+Am=GA5F.Equation (1) is now changed to the following form, which is known as fifth geometric arithmetic entropy.(11)ENTGA5F=logGA5F−1GA5F∑i=1q∑lm∈EiFlog2AlAmAl+Am2AlAmAl+Am.See [35, 44] for further information on these entropy measures.


## 1.1. Randić Entropy [43, 44]

IfΛlm=ℵ∧l×ℵ∧mα,withα=1,−1,1/2,−1/2, then(2)∑lm∈FEΛlm=∑lm∈FEℵ∧l×ℵ∧mα=Rα.Now (1) represent the Randic′ Entropy.(3)ENTRαF=logRα−1Rα∑i=1q∑lm∈FEiℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα.


## 1.2. Atom Bond Connectivity Entropy [45]

IfΛlm=ℵ∧l×ℵ∧m−2/ℵ∧l×ℵ∧m, then(4)∑lm∈FEΛlm=∑lm∈FEℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=ABCF.Thus (1) is converted in the following form:(5)ENTABCF=logABC−1ABC∑i=1q∑lm∈FEiℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m.


## 1.3. The Geometric Arithmetic Entropy [43, 44]

IfΛlm=2ℵ∧l×ℵ∧m/ℵ∧l+ℵ∧m, then(6)∑lm∈FEΛlm=∑lm∈FE2ℵ∧l×ℵ∧mℵ∧l+ℵ∧m=GAF.Now (1) takes the form as given below.(7)ENTGAF=logGA−1GA∑i=1q∑lm∈FEi2ℵ∧l×ℵ∧mℵ∧l+ℵ∧mlog2ℵ∧l×ℵ∧mℵ∧l+ℵ∧m.


## 1.4. The Fourth Atom Bond Connectivity Entropy [35]

IfΛlm=Al+Am−2/AlAm, then(8)∑lm∈EFΛlm=∑lm∈EFAl+Am−2AlAm=ABC4F.Now (1) converted in the following form as:(9)ENTABC4F=logABC4F−1ABC4F∑i=1q∑lm∈EiFlogAl+Am−2AlAmAl+Am−2/AlAm.


## 1.5. The Fifth Geometric Arithmetic Entropy [35]

IfΛlm=2AlAm/Al+Am, then(10)∑lm∈EFΛlm=∑lm∈EF2AlAmAl+Am=GA5F.Equation (1) is now changed to the following form, which is known as fifth geometric arithmetic entropy.(11)ENTGA5F=logGA5F−1GA5F∑i=1q∑lm∈EiFlog2AlAmAl+Am2AlAmAl+Am.See [35, 44] for further information on these entropy measures.


## 2. Formation of Triangular BenzenoidTx∀x∈N

Triangular benzenoids are a group of benzenoid molecular graphs and are denoted byTx, where x characterizes the number of hexagons at the bottom of the graph and 1/2xx+1 represents the total number of hexagons in Tx. Triangular benzenoids are a generalization of the benzene molecule C6H6, with benzene rings forming a triangular shape. In physics, chemistry, and nanosciences, the benzene molecule is a common molecule. Synthesizing aromatic chemicals is quite fruitful [46]. Raut [47] calculated some toplogical indices for the triangular benzenoid system. Hussain et al. [48] discussed the irregularity determinants of some benzenoid systems. Kwun [49] calculated degree-based indices by using M polynomials. For further details, see [50, 51]. The hexagons are placed in rows, with each row increasing by one hexagon. For T1, there are only one type of edges e1=2,2 and e1=6. Therefore, VT1=6 and ET1=6 while three kinds of edges are there in T2 e.g. e1=2,2, e2=2,3, e3=3,3 and e1=6, e2=6, e3=3. Therefore, VT−2=13 and ET2=15. Continuing in this way, VTx=x2+4x+1 and ETx=3/2xx+3. The subdivision graph of Tx and its line graph are demonstrated in Figure 1. It is to be noted that VLSTx=3xx+3 and ELSTx=3/23x2+7x−2.Figure 1
(a) Triangular benzenoidT5, (b) Subdivision of T5,  (c) The line graph of subdivision graph of T5.
(a)(b)(c)LetF=LSTx. i-e. F is the line graph of the subdivision graph of triangular benzenoid Tx. We will use the edge partition and vertices counting technique to compute our abstracted indices and entropies. The degree of each edge’s terminal vertices is used in the edge partitioning of F. It is easy to see that there are only three types of edges shown in Table 1.Table 1
Edge partition ofLSTx.
ℵ∧l,ℵ∧mNiSet of Edges2,22x+3E12,36x−1E23,33/23x2+x−4E3


### 2.1. Entropy Measure forLSTx

We’ll calculate the entropies ofF=LSTx in this section.


#### 2.1.1. Randic′ Entropy of LSTx

The Randic′ index and entropy for α=1,−1,1/2,−1/2, with the help of Table 1, and equation (3) is:(12)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α3x+9×log4α+6α6x−6×log6α+32α+123x2+x−4×log9α.By puttingα=1,−1,1/2,−1/2, in (3), we get the Randic′ entropies as given below:(13)ENTR1F=log3227x2+41x−52−12x+3×log43/227x2+41x−52−36x−1×log63/227x2+41x−52−27/23x2+x−4×log93/227x2+41x−52′ENTR−1F=log1126x2+23x+7+3/4x+3×log41/126x2+23x+7+x−1×log61/126x2+23x+7+1/63x2+x−4×log91/126x2+23x+7,ENTR1/2F=log329x2+7+46x−46−6x+3×log23/29x2+7+46x−46−66x−1×log63/29x2+7+46x−46−9/23x2+x−4×log33/29x2+7+46x−46,ENTR−1/2F=log1/23x2+22+6x+5+3/2x+3×log21/23x2+22+6x+5+6x−1×log61/23x2+22+6x+5+1/23x2+x−4×log31/23x2+22+6x+5.


#### 2.1.2. TheABC Entropy of LSTx

TheABC index and entropy measure with the help of Table 1 and equation (5) is:(14)ABCF=3x2+92+1x+32−4,ENTABCF=logABC−1ABC∑i=13∑lm∈EiFℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=log3x2+92+1x+32−4+1/29x+3×log23x2+9/2+1x+3/2−4−3x2+x−4×log2/33x2+9/2+1x+3/2−4.


#### 2.1.3. The Geometric Arithmetic Entropy ofLSTx

TheGA index and entropy measure with the help of Table 1 and equation (7) is:(15)GAF=92x2+3x1086+15−3546−5ENTGAF=logGA−1GA∑i=13∑lm∈EiF2ℵ∧l×ℵ∧mℵ∧l+ℵ∧mlog2ℵ∧l×ℵ∧mℵ∧l+ℵ∧m=log92x2+246+4510x+15−1265−126/5x−1×log26/59/2x2+246+45/10x+15−126/5.


#### 2.1.4. TheABC4 Entropy of LSTx

The edge partition of the graphLSTx is grounded on the degree addition of terminal vertices of every edge, as shown in Table 2.Table 2
Edge partition ofLSTx.
Al,AmNiSet of Edges4,49FE14,56FE25,53x−2FE35,86y−1FE48,83x−1FE58,96x−1FE69,93/23x2+2−5xFE7After simple calculations, by using Table2 subject to the condition that x≠1, we get(16)ABC4F=362+375+625x−2+31110+3148+152x−1+233x2−5x+2.By using (9), the ABC4 entropy as follows:(17)ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−36/2log6/4ABC4−37/5log7/25ABC4−62/5x−1log22/5ABC4−311/10x−1log11/210ABC4−314/8x−1log14/8ABC4−15/2x−1log15/62ABC4−2/33x2−5x+2log4/9ABC4.If we considerx=1, Then ABC4F=96/4, and ENTABC4F=2.1972.


#### 2.1.5. TheGA5 Entropy of LSTx

After some simple calculations, theGA5 index may be calculated using Table 2 under the constraint that x≠1.(18)GA5F=3+853+3x+241013+72217+3x−1+323x2−5n+2.Therefore, (11), with Table 2 converted in the form:(19)ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTGA5F=logGA5−85/3log45/9GA5−2410/13x−1log410/13GA5−722/17x−1log122/17GA5.


## 2.1. Entropy Measure forLSTx

We’ll calculate the entropies ofF=LSTx in this section.


### 2.1.1. Randic′ Entropy of LSTx

The Randic′ index and entropy for α=1,−1,1/2,−1/2, with the help of Table 1, and equation (3) is:(12)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α3x+9×log4α+6α6x−6×log6α+32α+123x2+x−4×log9α.By puttingα=1,−1,1/2,−1/2, in (3), we get the Randic′ entropies as given below:(13)ENTR1F=log3227x2+41x−52−12x+3×log43/227x2+41x−52−36x−1×log63/227x2+41x−52−27/23x2+x−4×log93/227x2+41x−52′ENTR−1F=log1126x2+23x+7+3/4x+3×log41/126x2+23x+7+x−1×log61/126x2+23x+7+1/63x2+x−4×log91/126x2+23x+7,ENTR1/2F=log329x2+7+46x−46−6x+3×log23/29x2+7+46x−46−66x−1×log63/29x2+7+46x−46−9/23x2+x−4×log33/29x2+7+46x−46,ENTR−1/2F=log1/23x2+22+6x+5+3/2x+3×log21/23x2+22+6x+5+6x−1×log61/23x2+22+6x+5+1/23x2+x−4×log31/23x2+22+6x+5.


### 2.1.2. TheABC Entropy of LSTx

TheABC index and entropy measure with the help of Table 1 and equation (5) is:(14)ABCF=3x2+92+1x+32−4,ENTABCF=logABC−1ABC∑i=13∑lm∈EiFℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=log3x2+92+1x+32−4+1/29x+3×log23x2+9/2+1x+3/2−4−3x2+x−4×log2/33x2+9/2+1x+3/2−4.


### 2.1.3. The Geometric Arithmetic Entropy ofLSTx

TheGA index and entropy measure with the help of Table 1 and equation (7) is:(15)GAF=92x2+3x1086+15−3546−5ENTGAF=logGA−1GA∑i=13∑lm∈EiF2ℵ∧l×ℵ∧mℵ∧l+ℵ∧mlog2ℵ∧l×ℵ∧mℵ∧l+ℵ∧m=log92x2+246+4510x+15−1265−126/5x−1×log26/59/2x2+246+45/10x+15−126/5.


### 2.1.4. TheABC4 Entropy of LSTx

The edge partition of the graphLSTx is grounded on the degree addition of terminal vertices of every edge, as shown in Table 2.Table 2
Edge partition ofLSTx.
Al,AmNiSet of Edges4,49FE14,56FE25,53x−2FE35,86y−1FE48,83x−1FE58,96x−1FE69,93/23x2+2−5xFE7After simple calculations, by using Table2 subject to the condition that x≠1, we get(16)ABC4F=362+375+625x−2+31110+3148+152x−1+233x2−5x+2.By using (9), the ABC4 entropy as follows:(17)ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−36/2log6/4ABC4−37/5log7/25ABC4−62/5x−1log22/5ABC4−311/10x−1log11/210ABC4−314/8x−1log14/8ABC4−15/2x−1log15/62ABC4−2/33x2−5x+2log4/9ABC4.If we considerx=1, Then ABC4F=96/4, and ENTABC4F=2.1972.


### 2.1.5. TheGA5 Entropy of LSTx

After some simple calculations, theGA5 index may be calculated using Table 2 under the constraint that x≠1.(18)GA5F=3+853+3x+241013+72217+3x−1+323x2−5n+2.Therefore, (11), with Table 2 converted in the form:(19)ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTGA5F=logGA5−85/3log45/9GA5−2410/13x−1log410/13GA5−722/17x−1log122/17GA5.


## 2.1.1. Randic′ Entropy of LSTx

The Randic′ index and entropy for α=1,−1,1/2,−1/2, with the help of Table 1, and equation (3) is:(12)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α3x+9×log4α+6α6x−6×log6α+32α+123x2+x−4×log9α.By puttingα=1,−1,1/2,−1/2, in (3), we get the Randic′ entropies as given below:(13)ENTR1F=log3227x2+41x−52−12x+3×log43/227x2+41x−52−36x−1×log63/227x2+41x−52−27/23x2+x−4×log93/227x2+41x−52′ENTR−1F=log1126x2+23x+7+3/4x+3×log41/126x2+23x+7+x−1×log61/126x2+23x+7+1/63x2+x−4×log91/126x2+23x+7,ENTR1/2F=log329x2+7+46x−46−6x+3×log23/29x2+7+46x−46−66x−1×log63/29x2+7+46x−46−9/23x2+x−4×log33/29x2+7+46x−46,ENTR−1/2F=log1/23x2+22+6x+5+3/2x+3×log21/23x2+22+6x+5+6x−1×log61/23x2+22+6x+5+1/23x2+x−4×log31/23x2+22+6x+5.


## 2.1.2. TheABC Entropy of LSTx

TheABC index and entropy measure with the help of Table 1 and equation (5) is:(14)ABCF=3x2+92+1x+32−4,ENTABCF=logABC−1ABC∑i=13∑lm∈EiFℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=log3x2+92+1x+32−4+1/29x+3×log23x2+9/2+1x+3/2−4−3x2+x−4×log2/33x2+9/2+1x+3/2−4.


## 2.1.3. The Geometric Arithmetic Entropy ofLSTx

TheGA index and entropy measure with the help of Table 1 and equation (7) is:(15)GAF=92x2+3x1086+15−3546−5ENTGAF=logGA−1GA∑i=13∑lm∈EiF2ℵ∧l×ℵ∧mℵ∧l+ℵ∧mlog2ℵ∧l×ℵ∧mℵ∧l+ℵ∧m=log92x2+246+4510x+15−1265−126/5x−1×log26/59/2x2+246+45/10x+15−126/5.


## 2.1.4. TheABC4 Entropy of LSTx

The edge partition of the graphLSTx is grounded on the degree addition of terminal vertices of every edge, as shown in Table 2.Table 2
Edge partition ofLSTx.
Al,AmNiSet of Edges4,49FE14,56FE25,53x−2FE35,86y−1FE48,83x−1FE58,96x−1FE69,93/23x2+2−5xFE7After simple calculations, by using Table2 subject to the condition that x≠1, we get(16)ABC4F=362+375+625x−2+31110+3148+152x−1+233x2−5x+2.By using (9), the ABC4 entropy as follows:(17)ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−36/2log6/4ABC4−37/5log7/25ABC4−62/5x−1log22/5ABC4−311/10x−1log11/210ABC4−314/8x−1log14/8ABC4−15/2x−1log15/62ABC4−2/33x2−5x+2log4/9ABC4.If we considerx=1, Then ABC4F=96/4, and ENTABC4F=2.1972.


## 2.1.5. TheGA5 Entropy of LSTx

After some simple calculations, theGA5 index may be calculated using Table 2 under the constraint that x≠1.(18)GA5F=3+853+3x+241013+72217+3x−1+323x2−5n+2.Therefore, (11), with Table 2 converted in the form:(19)ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTGA5F=logGA5−85/3log45/9GA5−2410/13x−1log410/13GA5−722/17x−1log122/17GA5.


## 3. Formation of Hexagonal Parallelogram NanotubesHx,y, ∀x,y∈N

Hexagonal parallelogram nanotubes are formed by arranging hexagons in a parallelogram fashion. Baig et al. [52] computed counting polynomials of benzoid carbon nanotubes. Also, see [53]. We will denote this structure by Hx,y∀x,y∈N, in which x and y represent the quantity of hexagons in any row and column respectively. Also, the order and size of Hx,y is 2x+y+xy and 3xy+2x+2y−1 respectively. The subdivision graph of Hx,y and its line graph is shown in Figure 2, see [46]. Let F=LSHx,y, then FV=23xy+2x+2y−1 and FE=9xy+4x+4y−5. To compute our results, we will use edge partition technique which is grounded on the degree of terminal vertices of every edge. It is to be noted that there are only three types of edges, see Figure 2. The edge partition of chemical graph LSHx,y depending on the degree of terminal vertices is presented in Table 3.Figure 2
(a) Hexagonal parallelogramHx,y, (b) Subdivision of Hx,y,  (c) The line graph of subdivision graph of Hx,y.
(a)(b)(c)Table 3
Edge partition ofLSHx,y.
ℵ∧l,ℵ∧mNiKinds of Edges2,224+y+xFE12,34−2+y+xFE23,39xy−2m−2n−5FE3


### 3.1. Entropy Measure forLSHx,y

We will enumerate the entropies ofF=LSHx,y in this section.


#### 3.1.1. Randić Entropy ofF

The Randic′ index for α=1,−1,1/2,−1/2, by using Table 3 is:(20)RαF=2x+y+4×4α+4x+y−2×6α+9xy−2x−2y−5×9α.So the (3) with Table 3 gives the Randic′ entropy and is converted in the form:(21)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α2x+2y+8×log4α+6α4x+4y−8×log6α+9α9xy−2x−2y−5×log9α.Now substituteα=1,−1,1/2,−1/2, in (20), we get the Randic′ entropies as given below:(22)ENTR1F=log81xy+14x+y−61−8x+y+4×481xy+14x+y−61−24x+y−2×log681xy+14x+y−61−99xy−2x−2y−5×log981xy+14x+y−61ENTR−1F=logxy+1718x+y+19+1/2x+y+4×4xy+17/18x+y+1/9+2/3x+y−2×log6xy+17/18x+y+1/9+1/99xy−2x−2y−5×log9xy+17/18x+y+1/9.ENTR1/2F=log27xy+46−2x+y+1−86−4x+y+4×227xy+46−2x+y+1−86−46x+y−2×log627xy+46−2x+y+1−86−939xy−2x−2y−5×log327xy+46−2x+y+1−86,ENTR−1/2F=log3xy+13+46x+y+73−86+x+y+4×log23xy+1/3+4/6x+y+7/3−8/6+4/6x+y−2×log63xy+1/3+4/6x+y+7/3−8/6+1/39xy−2x−2y−5×log93xy+1/3+4/6x+y+7/3−8/6.


#### 3.1.2. TheABC Entropy of F

With the use of Table3 and equation (5), we can calculate the ABC index and entropy measure as follows:(23)ABCF=6xy+92−43x+y−103.Therefore, the equation (5), with Table 3 becomes as following and is called the atom bond connectivity entropy.(24)ENTABCF=logABC−1ABC∑i=13∑lm∈EiFℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=log6xy+92−43x+y−103+2x+y+4×26xy+92−4/3x+y−10/3+22x+y−2×log66xy+92−4/3x+y−10/3−2/39xy−2x−2y−5×log2/36xy+92−4/3x+y−10/3.


#### 3.1.3. The Geometric Arithmetic Entropy ofF

We can calculate theGA index and entropy measure using Table 3 and equation (7) as follows:(25)GAF=1545xy+86x+y+15−166,ENTGAF=log1545xy+86x+y+15−166−86/5x+y−2×log26/51/545xy+86x+y+15−166.


#### 3.1.4. TheABC4 Entropy of F

Case 1.
whenx > 1, y≠1
The edge partition ofLSHx,y is shown in Table 4.
Therefore, theABC4 index and entropy measure with the help of Table 4 and equation (9) yield as:(26)ABC4F=4xy+425+21110+144+303−329x+y+26+475−1625−41110−142−2303+289.
SinceF has seven kinds of edges, So (9) by using Table 4 is converted in the form:(27)ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−26log6/4ABC4−47/5log7/25ABC4−42/5x+y−4log22/5ABC4−211/10x+y−2log11/210ABC4−14/4x+y−2log14/8ABC4−215/32x+y−2log15/62ABC4−4/99xy−8x−8y+7log4/9ABC4.Table 4
Edge partition ofLSHx,y.
Al,AmNiKinds of edges4,48FE14,58FE25,52−4+y+xFE35,84−2+y+xFE48,82−2+x+yFE58,92−2+x+yFE69,99xy−8x−8y+7FE7Case 2.
whenx=1, y≠1
By using the same process, we get the closed expressions for theABC4 index and ABC4 entropy as:(28)BC4F=425+21110+144+303+49y+562+275−825−21110−303−144−A94,ENTABC4F=logABC4−56/2log6/4ABC4−27/5log7/25ABC4−42/5y−2log22/5ABC4−211/10y−1log11/210ABC4−14/4y−1log14/8ABC4−215/32y−1log15/62ABC4−4/9y−1log4/9ABC4.


#### 3.1.5. The Fifth Geometric Arithmetic Entropy ofF

Case 3.
whenx > 1, y≠1The fifth geometric arithmetic entropy can be estimated by using (11), and Table 4 in the following manner:(29)GA5F=9xy+161013+48217−4x+y+3+3259−321013−96217.
So the (11), with Table 4 can be written as:(30)ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm=logGA5−325/9log45/9GA5−1610/13x+y−2log410/13GA5−482/17x+y−2log122/17GA5.Case 4.
whenx=1, y≠1By using Table 5 and using (11) we get the closed expressions for the GA5 index and GA5 entropy as:(31)GA5F=5+161013+48217y+3+1659−161013−48217−161013,ENTGA5F=logGA5−165/9log45/9GA5−1610/13y−1log410/13GA5−482/17y−1log122/17GA5.Table 5
Edge partition ofLSHx,y, for x=1.
Al,AmNiKinds of edges4,410FE14,54FE25,52y−2FE35,84y−1FE48,82y−1FE58,92y−1FE69,9y−1FE7


## 3.1. Entropy Measure forLSHx,y

We will enumerate the entropies ofF=LSHx,y in this section.


### 3.1.1. Randić Entropy ofF

The Randic′ index for α=1,−1,1/2,−1/2, by using Table 3 is:(20)RαF=2x+y+4×4α+4x+y−2×6α+9xy−2x−2y−5×9α.So the (3) with Table 3 gives the Randic′ entropy and is converted in the form:(21)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α2x+2y+8×log4α+6α4x+4y−8×log6α+9α9xy−2x−2y−5×log9α.Now substituteα=1,−1,1/2,−1/2, in (20), we get the Randic′ entropies as given below:(22)ENTR1F=log81xy+14x+y−61−8x+y+4×481xy+14x+y−61−24x+y−2×log681xy+14x+y−61−99xy−2x−2y−5×log981xy+14x+y−61ENTR−1F=logxy+1718x+y+19+1/2x+y+4×4xy+17/18x+y+1/9+2/3x+y−2×log6xy+17/18x+y+1/9+1/99xy−2x−2y−5×log9xy+17/18x+y+1/9.ENTR1/2F=log27xy+46−2x+y+1−86−4x+y+4×227xy+46−2x+y+1−86−46x+y−2×log627xy+46−2x+y+1−86−939xy−2x−2y−5×log327xy+46−2x+y+1−86,ENTR−1/2F=log3xy+13+46x+y+73−86+x+y+4×log23xy+1/3+4/6x+y+7/3−8/6+4/6x+y−2×log63xy+1/3+4/6x+y+7/3−8/6+1/39xy−2x−2y−5×log93xy+1/3+4/6x+y+7/3−8/6.


### 3.1.2. TheABC Entropy of F

With the use of Table3 and equation (5), we can calculate the ABC index and entropy measure as follows:(23)ABCF=6xy+92−43x+y−103.Therefore, the equation (5), with Table 3 becomes as following and is called the atom bond connectivity entropy.(24)ENTABCF=logABC−1ABC∑i=13∑lm∈EiFℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=log6xy+92−43x+y−103+2x+y+4×26xy+92−4/3x+y−10/3+22x+y−2×log66xy+92−4/3x+y−10/3−2/39xy−2x−2y−5×log2/36xy+92−4/3x+y−10/3.


### 3.1.3. The Geometric Arithmetic Entropy ofF

We can calculate theGA index and entropy measure using Table 3 and equation (7) as follows:(25)GAF=1545xy+86x+y+15−166,ENTGAF=log1545xy+86x+y+15−166−86/5x+y−2×log26/51/545xy+86x+y+15−166.


### 3.1.4. TheABC4 Entropy of F

Case 1.
whenx > 1, y≠1
The edge partition ofLSHx,y is shown in Table 4.
Therefore, theABC4 index and entropy measure with the help of Table 4 and equation (9) yield as:(26)ABC4F=4xy+425+21110+144+303−329x+y+26+475−1625−41110−142−2303+289.
SinceF has seven kinds of edges, So (9) by using Table 4 is converted in the form:(27)ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−26log6/4ABC4−47/5log7/25ABC4−42/5x+y−4log22/5ABC4−211/10x+y−2log11/210ABC4−14/4x+y−2log14/8ABC4−215/32x+y−2log15/62ABC4−4/99xy−8x−8y+7log4/9ABC4.Table 4
Edge partition ofLSHx,y.
Al,AmNiKinds of edges4,48FE14,58FE25,52−4+y+xFE35,84−2+y+xFE48,82−2+x+yFE58,92−2+x+yFE69,99xy−8x−8y+7FE7Case 2.
whenx=1, y≠1
By using the same process, we get the closed expressions for theABC4 index and ABC4 entropy as:(28)BC4F=425+21110+144+303+49y+562+275−825−21110−303−144−A94,ENTABC4F=logABC4−56/2log6/4ABC4−27/5log7/25ABC4−42/5y−2log22/5ABC4−211/10y−1log11/210ABC4−14/4y−1log14/8ABC4−215/32y−1log15/62ABC4−4/9y−1log4/9ABC4.


### 3.1.5. The Fifth Geometric Arithmetic Entropy ofF

Case 3.
whenx > 1, y≠1The fifth geometric arithmetic entropy can be estimated by using (11), and Table 4 in the following manner:(29)GA5F=9xy+161013+48217−4x+y+3+3259−321013−96217.
So the (11), with Table 4 can be written as:(30)ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm=logGA5−325/9log45/9GA5−1610/13x+y−2log410/13GA5−482/17x+y−2log122/17GA5.Case 4.
whenx=1, y≠1By using Table 5 and using (11) we get the closed expressions for the GA5 index and GA5 entropy as:(31)GA5F=5+161013+48217y+3+1659−161013−48217−161013,ENTGA5F=logGA5−165/9log45/9GA5−1610/13y−1log410/13GA5−482/17y−1log122/17GA5.Table 5
Edge partition ofLSHx,y, for x=1.
Al,AmNiKinds of edges4,410FE14,54FE25,52y−2FE35,84y−1FE48,82y−1FE58,92y−1FE69,9y−1FE7


## 3.1.1. Randić Entropy ofF

The Randic′ index for α=1,−1,1/2,−1/2, by using Table 3 is:(20)RαF=2x+y+4×4α+4x+y−2×6α+9xy−2x−2y−5×9α.So the (3) with Table 3 gives the Randic′ entropy and is converted in the form:(21)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α2x+2y+8×log4α+6α4x+4y−8×log6α+9α9xy−2x−2y−5×log9α.Now substituteα=1,−1,1/2,−1/2, in (20), we get the Randic′ entropies as given below:(22)ENTR1F=log81xy+14x+y−61−8x+y+4×481xy+14x+y−61−24x+y−2×log681xy+14x+y−61−99xy−2x−2y−5×log981xy+14x+y−61ENTR−1F=logxy+1718x+y+19+1/2x+y+4×4xy+17/18x+y+1/9+2/3x+y−2×log6xy+17/18x+y+1/9+1/99xy−2x−2y−5×log9xy+17/18x+y+1/9.ENTR1/2F=log27xy+46−2x+y+1−86−4x+y+4×227xy+46−2x+y+1−86−46x+y−2×log627xy+46−2x+y+1−86−939xy−2x−2y−5×log327xy+46−2x+y+1−86,ENTR−1/2F=log3xy+13+46x+y+73−86+x+y+4×log23xy+1/3+4/6x+y+7/3−8/6+4/6x+y−2×log63xy+1/3+4/6x+y+7/3−8/6+1/39xy−2x−2y−5×log93xy+1/3+4/6x+y+7/3−8/6.


## 3.1.2. TheABC Entropy of F

With the use of Table3 and equation (5), we can calculate the ABC index and entropy measure as follows:(23)ABCF=6xy+92−43x+y−103.Therefore, the equation (5), with Table 3 becomes as following and is called the atom bond connectivity entropy.(24)ENTABCF=logABC−1ABC∑i=13∑lm∈EiFℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧mlogℵ∧l+ℵ∧m−2ℵ∧l×ℵ∧m=log6xy+92−43x+y−103+2x+y+4×26xy+92−4/3x+y−10/3+22x+y−2×log66xy+92−4/3x+y−10/3−2/39xy−2x−2y−5×log2/36xy+92−4/3x+y−10/3.


## 3.1.3. The Geometric Arithmetic Entropy ofF

We can calculate theGA index and entropy measure using Table 3 and equation (7) as follows:(25)GAF=1545xy+86x+y+15−166,ENTGAF=log1545xy+86x+y+15−166−86/5x+y−2×log26/51/545xy+86x+y+15−166.


## 3.1.4. TheABC4 Entropy of F

Case 1.
whenx > 1, y≠1
The edge partition ofLSHx,y is shown in Table 4.
Therefore, theABC4 index and entropy measure with the help of Table 4 and equation (9) yield as:(26)ABC4F=4xy+425+21110+144+303−329x+y+26+475−1625−41110−142−2303+289.
SinceF has seven kinds of edges, So (9) by using Table 4 is converted in the form:(27)ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−26log6/4ABC4−47/5log7/25ABC4−42/5x+y−4log22/5ABC4−211/10x+y−2log11/210ABC4−14/4x+y−2log14/8ABC4−215/32x+y−2log15/62ABC4−4/99xy−8x−8y+7log4/9ABC4.Table 4
Edge partition ofLSHx,y.
Al,AmNiKinds of edges4,48FE14,58FE25,52−4+y+xFE35,84−2+y+xFE48,82−2+x+yFE58,92−2+x+yFE69,99xy−8x−8y+7FE7Case 2.
whenx=1, y≠1
By using the same process, we get the closed expressions for theABC4 index and ABC4 entropy as:(28)BC4F=425+21110+144+303+49y+562+275−825−21110−303−144−A94,ENTABC4F=logABC4−56/2log6/4ABC4−27/5log7/25ABC4−42/5y−2log22/5ABC4−211/10y−1log11/210ABC4−14/4y−1log14/8ABC4−215/32y−1log15/62ABC4−4/9y−1log4/9ABC4.


## 3.1.5. The Fifth Geometric Arithmetic Entropy ofF

Case 3.
whenx > 1, y≠1The fifth geometric arithmetic entropy can be estimated by using (11), and Table 4 in the following manner:(29)GA5F=9xy+161013+48217−4x+y+3+3259−321013−96217.
So the (11), with Table 4 can be written as:(30)ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm=logGA5−325/9log45/9GA5−1610/13x+y−2log410/13GA5−482/17x+y−2log122/17GA5.Case 4.
whenx=1, y≠1By using Table 5 and using (11) we get the closed expressions for the GA5 index and GA5 entropy as:(31)GA5F=5+161013+48217y+3+1659−161013−48217−161013,ENTGA5F=logGA5−165/9log45/9GA5−1610/13y−1log410/13GA5−482/17y−1log122/17GA5.Table 5
Edge partition ofLSHx,y, for x=1.
Al,AmNiKinds of edges4,410FE14,54FE25,52y−2FE35,84y−1FE48,82y−1FE58,92y−1FE69,9y−1FE7


## 4. Formation from Fusion of Zigzag-Edge Coronoid with StarpheneZCSx,y,z Nanotubes

If a zigzag-edge coronoidZCx,y,z is fused with a starphene Stx,y,z, then we will obtain a composite benzenoid. It is to b noted that VZCSx,y,z=36x−54 and EZCSx,y,z=−63+15z+y+x. The subdivision graph of ZCSx,y,z and its line graph are illustrated in Figure 3. We can see from figures that the order and the size in the line graph of the subdivision graph of ZCSx,y,z are −126+30z+y+x and −153+39z+y+x respectively [46]. Let F represents the subdivision graph of ZCSx,y,z’s line graph. The edge division is determined by the degree of each edge’s terminal vertices. Table 6 illustrates this.Figure 3
(a)ZCS4,4,4, (b) subdivision of ZCS4,4,4,  (c) LSZCS4,4,4.
(a)(b)(c)Table 6
Edge partition ofLSZCS.
ℵ∧l,ℵ∧mNiKinds of Edges2,26−5+z+y+xFE12,312−7+z+y+xFE23,3−39+21z+y+xFE3


### 4.1. Entropy Measure forLSZCSx,y,z

We’ll calculate the entropies ofF=LSZCSx,y,z in this section.


#### 4.1.1. Randic′ Entropy of F

Forα=1,−1,1/2,−1/2, the Randic′ index with the help of Table 1 is(32)RαF=6x+y+z−5×4α+12x+y+z−7×6α+21x+21y+21z−39×9α.Using (3) Randic′ entropy is:(33)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α6x+y+z−5×log4α+6α12x+y+z−7×log6α+21x+y+z−39×log9α.By puttingα=1,−1,1/2,−1/2, in (32), we get the Randic′ entropies as given below:(34)ENTR1F=log−975+285z+y+x−24−5+z+y+x×log4−975+285z+y+x−72x+y+z−7×log6−975+285z+y+x−189z+y+x−351×log9−975+285z+y+x,ENTR−1F=log−1316+356z+y+x+3/2−5+z+y+x×log4−131/6+35/6z+y+x+2−7+z+y+x×log6−131/6+35/6z+y+x+1/3−13+7z+y+x×log9−131/6+35/6z+y+x,ENTR1/2F=log3+126x+y+z−177−846−12x+y+z−5×log23+126x+y+z−177−846−66x+y+z−7×log63+126x+y+z−177−846−97x+y+z−13×log33+126x+y+z−177−846,ENTR−1/2F=log10+26x+y+z−28−146+3x+y+z−5×log210+26x+y+z−28−146+26x+y+z−7×log610+26x+y+z−28−146+7x+y+z−13×log310+26x+y+z−28−146.


#### 4.1.2. TheABC Entropy of F

TheABC index and entropy measure with the help of Table 6 and equation (5) are:(35)ABCF=14+92x+y+z−26−572,ENTABCF=log14+92x+y+z−26−572+323x+y+z−19×log214+92x+y+z−26−572−14x+y+z−26log2/314+92x+y+z−26−572.


#### 4.1.3. The Geometric Arithmetic Entropy ofF

TheGA index and corresponding entropy with the help of Table 6 and equation (7) are:(36)GAF=x+y+z27+246/5−69−1686/5,ENTGAF=logx+y+z27+246/5−69−1686/5−246/5x+y+z−7×log26/5x+y+z27+246/5−69−1686/5.


#### 4.1.4. TheABC4 entropy of F

Table7 shows the graph LSZCSx,y,z’s edge partition, which is based on the degree addition of each edge’s terminal vertices.Table 7
Edge partition ofLSZCSx,y,z established on degree sum of terminal vertices, for every x=y=z≥4
Al,AmNiKinds of Edges4,46FE14,512FE25,56x+y+z−8FE35,812x+y+z−7FE48,86x+y+z−9FE58,912x+y+z−5FE69,93x+y+z+25FE7After simple calculations, theABC4 index and entropy measure with the help of Table 7 and equation (9) subject to the condition that x=y=z≥41(37)ABC4F=x+y+z30+43+1225+3144+61110−530+1003−9625+27144−421110+362+675,ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−36/2log6/4ABC4−122/5x+y+z−8log22/5ABC4−611/10x+y+z−7log11/210ABC4−314/4x+y+x−9log14/8ABC4−30x+y+z−5log15/62ABC4−4/3x+y+z+25log4/9ABC4−67/5log7/25ABC4.


#### 4.1.5. TheGA5 Entropy of F

After some simple calculations, theGA5 index and corresponding entropy measure with the help of Table 7 and equation (11) subject to the condition that x=y=z≥4.(38)GA5F=x+y+z15+481013+144217+3+1653−3361013−720217ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTGA5F=logGA5−165/3log45/9GA5−4810/13x+y+z−7log410/13GA5−1442/17x+y+z−5log122/17GA5.


## 4.1. Entropy Measure forLSZCSx,y,z

We’ll calculate the entropies ofF=LSZCSx,y,z in this section.


### 4.1.1. Randic′ Entropy of F

Forα=1,−1,1/2,−1/2, the Randic′ index with the help of Table 1 is(32)RαF=6x+y+z−5×4α+12x+y+z−7×6α+21x+21y+21z−39×9α.Using (3) Randic′ entropy is:(33)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α6x+y+z−5×log4α+6α12x+y+z−7×log6α+21x+y+z−39×log9α.By puttingα=1,−1,1/2,−1/2, in (32), we get the Randic′ entropies as given below:(34)ENTR1F=log−975+285z+y+x−24−5+z+y+x×log4−975+285z+y+x−72x+y+z−7×log6−975+285z+y+x−189z+y+x−351×log9−975+285z+y+x,ENTR−1F=log−1316+356z+y+x+3/2−5+z+y+x×log4−131/6+35/6z+y+x+2−7+z+y+x×log6−131/6+35/6z+y+x+1/3−13+7z+y+x×log9−131/6+35/6z+y+x,ENTR1/2F=log3+126x+y+z−177−846−12x+y+z−5×log23+126x+y+z−177−846−66x+y+z−7×log63+126x+y+z−177−846−97x+y+z−13×log33+126x+y+z−177−846,ENTR−1/2F=log10+26x+y+z−28−146+3x+y+z−5×log210+26x+y+z−28−146+26x+y+z−7×log610+26x+y+z−28−146+7x+y+z−13×log310+26x+y+z−28−146.


### 4.1.2. TheABC Entropy of F

TheABC index and entropy measure with the help of Table 6 and equation (5) are:(35)ABCF=14+92x+y+z−26−572,ENTABCF=log14+92x+y+z−26−572+323x+y+z−19×log214+92x+y+z−26−572−14x+y+z−26log2/314+92x+y+z−26−572.


### 4.1.3. The Geometric Arithmetic Entropy ofF

TheGA index and corresponding entropy with the help of Table 6 and equation (7) are:(36)GAF=x+y+z27+246/5−69−1686/5,ENTGAF=logx+y+z27+246/5−69−1686/5−246/5x+y+z−7×log26/5x+y+z27+246/5−69−1686/5.


### 4.1.4. TheABC4 entropy of F

Table7 shows the graph LSZCSx,y,z’s edge partition, which is based on the degree addition of each edge’s terminal vertices.Table 7
Edge partition ofLSZCSx,y,z established on degree sum of terminal vertices, for every x=y=z≥4
Al,AmNiKinds of Edges4,46FE14,512FE25,56x+y+z−8FE35,812x+y+z−7FE48,86x+y+z−9FE58,912x+y+z−5FE69,93x+y+z+25FE7After simple calculations, theABC4 index and entropy measure with the help of Table 7 and equation (9) subject to the condition that x=y=z≥41(37)ABC4F=x+y+z30+43+1225+3144+61110−530+1003−9625+27144−421110+362+675,ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−36/2log6/4ABC4−122/5x+y+z−8log22/5ABC4−611/10x+y+z−7log11/210ABC4−314/4x+y+x−9log14/8ABC4−30x+y+z−5log15/62ABC4−4/3x+y+z+25log4/9ABC4−67/5log7/25ABC4.


### 4.1.5. TheGA5 Entropy of F

After some simple calculations, theGA5 index and corresponding entropy measure with the help of Table 7 and equation (11) subject to the condition that x=y=z≥4.(38)GA5F=x+y+z15+481013+144217+3+1653−3361013−720217ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTGA5F=logGA5−165/3log45/9GA5−4810/13x+y+z−7log410/13GA5−1442/17x+y+z−5log122/17GA5.


## 4.1.1. Randic′ Entropy of F

Forα=1,−1,1/2,−1/2, the Randic′ index with the help of Table 1 is(32)RαF=6x+y+z−5×4α+12x+y+z−7×6α+21x+21y+21z−39×9α.Using (3) Randic′ entropy is:(33)ENTRαF=logRα−1Rα∑i=13∑lm∈EiFℵ∧l×ℵ∧mαlogℵ∧l×ℵ∧mα=logRα−1Rα4α6x+y+z−5×log4α+6α12x+y+z−7×log6α+21x+y+z−39×log9α.By puttingα=1,−1,1/2,−1/2, in (32), we get the Randic′ entropies as given below:(34)ENTR1F=log−975+285z+y+x−24−5+z+y+x×log4−975+285z+y+x−72x+y+z−7×log6−975+285z+y+x−189z+y+x−351×log9−975+285z+y+x,ENTR−1F=log−1316+356z+y+x+3/2−5+z+y+x×log4−131/6+35/6z+y+x+2−7+z+y+x×log6−131/6+35/6z+y+x+1/3−13+7z+y+x×log9−131/6+35/6z+y+x,ENTR1/2F=log3+126x+y+z−177−846−12x+y+z−5×log23+126x+y+z−177−846−66x+y+z−7×log63+126x+y+z−177−846−97x+y+z−13×log33+126x+y+z−177−846,ENTR−1/2F=log10+26x+y+z−28−146+3x+y+z−5×log210+26x+y+z−28−146+26x+y+z−7×log610+26x+y+z−28−146+7x+y+z−13×log310+26x+y+z−28−146.


## 4.1.2. TheABC Entropy of F

TheABC index and entropy measure with the help of Table 6 and equation (5) are:(35)ABCF=14+92x+y+z−26−572,ENTABCF=log14+92x+y+z−26−572+323x+y+z−19×log214+92x+y+z−26−572−14x+y+z−26log2/314+92x+y+z−26−572.


## 4.1.3. The Geometric Arithmetic Entropy ofF

TheGA index and corresponding entropy with the help of Table 6 and equation (7) are:(36)GAF=x+y+z27+246/5−69−1686/5,ENTGAF=logx+y+z27+246/5−69−1686/5−246/5x+y+z−7×log26/5x+y+z27+246/5−69−1686/5.


## 4.1.4. TheABC4 entropy of F

Table7 shows the graph LSZCSx,y,z’s edge partition, which is based on the degree addition of each edge’s terminal vertices.Table 7
Edge partition ofLSZCSx,y,z established on degree sum of terminal vertices, for every x=y=z≥4
Al,AmNiKinds of Edges4,46FE14,512FE25,56x+y+z−8FE35,812x+y+z−7FE48,86x+y+z−9FE58,912x+y+z−5FE69,93x+y+z+25FE7After simple calculations, theABC4 index and entropy measure with the help of Table 7 and equation (9) subject to the condition that x=y=z≥41(37)ABC4F=x+y+z30+43+1225+3144+61110−530+1003−9625+27144−421110+362+675,ENTABC4F=logABC4−1ABC4∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTABC4F=logABC4−36/2log6/4ABC4−122/5x+y+z−8log22/5ABC4−611/10x+y+z−7log11/210ABC4−314/4x+y+x−9log14/8ABC4−30x+y+z−5log15/62ABC4−4/3x+y+z+25log4/9ABC4−67/5log7/25ABC4.


## 4.1.5. TheGA5 Entropy of F

After some simple calculations, theGA5 index and corresponding entropy measure with the help of Table 7 and equation (11) subject to the condition that x=y=z≥4.(38)GA5F=x+y+z15+481013+144217+3+1653−3361013−720217ENTGA5F=logGA5−1GA5∑i=17∑lm∈EiFAl+Am−2AlAmlogAl+Am−2AlAm,ENTGA5F=logGA5−165/3log45/9GA5−4810/13x+y+z−7log410/13GA5−1442/17x+y+z−5log122/17GA5.


## 5. Concluding remarks for Computed Results

The applications of information-theoretic framework in many disciplines of study, such as biology, physics, engineering, and social sciences, have grown exponentially in the recent two decades. This phenomenal increase has been particularly impressive in the fields of soft computing, molecular biology, and information technology. As a result, the scientists may find our numerical and graphical results useful [54, 55]. The entropy function is monotonic, which means that as the size of a chemical structure increases, so does the entropy measure, and as the entropy of a system increases, so does the uncertainty regarding its reaction.ForLSTx, the numerical and graphical results are shown in Tables 8 and 9 and Figures 4–7. In Table 9, the fifth arithmetic geometric entropy is zero which shows that the process is deterministic for x=1. When the chemical structure LSTx expands, the Randic′ entropy for α=1/2 develops more quickly than other entropy measurements of LSTx, whereas the Randic′ entropy for α=−1/2 develops more slowly. This demonstrates that different topologies have varied entropy characteristics. For LSHx,y, the numerical and graphical results are shown in Tables 10–13 and Figures 8–12. When the chemical structure LSHx,y expands, the geometric arithmetic entropy develops more quickly than other entropy measurements of LSHx,y, whereas the ABC4 entropy develops more slowly. Finally, for LSZCSx,y,z, the numerical and graphical results are shown in Table 14 and Figures 13–16. When the chemical structure LSZCSx,y,z expands, the geometric arithmetic entropy develops more quickly than other entropy measurements of LSZCSx,y,z, whereas the Randic′ entropy for α=−1 develops more slowly.Table 8
Comparison of randic entropies forLSTx.
xENTR1ENTR−1ENTR1/2ENTR−1/2[46]0.40552.55902.48492.6263[52]3.18633.04633.56673.5970[25]4.03163.67674.22034.2280[26]4.57974.29284.69814.6991[24]4.99454.87145.07795.0764[23]5.33125.41075.39425.3918[27]5.61595.91315.66585.6631[2]5.86326.38205.90415.9013[56]6.08206.82086.11646.1136[31]6.27857.23256.30806.3053Table 9
Comparison ofENTABC, ENTGA, ENTABC4, and ENTGA5 for LSTx.
xENTABCENTGAENTABC4ENTGA5[46]2.31162.48492.19720[52]3.52393.58353.57493.5835[25]4.20254.23414.22634.2341[26]4.68974.70954.70284.7095[24]5.07395.08765.08175.0876[23]5.39265.40275.39755.4026[27]5.66555.67335.66875.6733[2]5.90465.910875.90665.9108[56]6.11746.12256.11876.1225[31]6.30936.31356.31006.3135Figure 4
(a)R1 entropy, (b) R−1 entropy.
(a)(b)Figure 5
(a)R1/2 entropy, (b) R−1/2 entropy.
(a)(b)Figure 6
(a) TheABC entropy, (b) The GA entropy.
(a)(b)Figure 7
(a) TheABC4 entropy, (b) The GA5, entropy.
(a)(b)Table 10
Comparison of randic entropies forLSHx,y.
x,yENTR1ENTR−1ENTR1/2ENTR−1/21,12.48492.48492.48492.48492,23.79173.78303.83443.83323,34.56354.54284.59334.59064,45.10965.08725.13235.12945,55.53455.51295.55305.55026,65.88335.86305.89885.89627,76.17946.16156.19286.19048,86.43686.41946.44866.44649,96.66466.64836.67516.673110,106.86886.53706.87836.8822Table 11
Comparison ofENTABC and ENTGA entropies for LSHx,y.
x,yENTABCENTGA1,12.48492.48492,23.84973.85013,34.60484.60514,45.14135.14165,55.56045.56076,65.90515.90537,76.19826.19858,86.45346.45369,96.67946.679610,106.88226.8824Table 12
Comparison ofENTABC4 and ENTGA5 Entropies for LSHx,y, x > 1 and y≠1.
x,yENTABC4ENTGA52,23.78793.48223,34.53872.25964,45.07834.83875,55.50185.29526,65.85095.67047,76.14815.98828,86.40686.26369,96.63606.506410,106.84176.7234Table 13
Comparison ofENTABC4 and ENTGA5 entropies for LSHx,y, x=1 and y≠1.
yENTABC4ENTGA5[52]3.18463.2958[25]3.59333.6888[26]3.88843.9702[24]4.11844.1896[23]4.30644.3694[27]4.46534.5217[2]4.60274.6539[56]4.72384.7706[31]4.83194.8751Figure 8
(a)R1 entropy, (b)R−1 entropy.
(a)(b)Figure 9
(a)R1/2 entropy, (b)R−1/2 entropy.
(a)(b)Figure 10
(a) TheABC entropy, (b) The GA, entropy.
(a)(b)Figure 11
(a) TheABC4 entropy, (b) The GA5 entropy, x≥1, y≠1.
(a)(b)Figure 12
(a) TheABC4 entropy, (b) The GA5 entropy x=1, y≠1.
(a)(b)Table 14
Comparison of randic entropies forLSZCSx,y,z.
x,y,zENTR1ENTR−1ENTR1/2ENTR−1/24,4,45.72005.700605.74325.74075,5,56.03426.01656.05876.05656,6,66.27306.25646.29826.29617,7,76.46576.44976.49136.48938,8,86.62726.61176.65316.65119,9,96.76626.75116.79236.790410,10,106.88836.87346.91456.9126Figure 13
(a)R1 entropy, (b)R−1 entropy.
(a)(b)Figure 14
(a)R1/2 entropy, (b)R1/2 entropy.
(a)(b)Figure 15
(a)ABC entropy, (b)The GA, entropy.
(a)(b)Figure 16
(a)ABC4 entropy, (b)GA5 entropy.
(a)(b)The novelty of this article is that entropies are computed for three types of benzenoid systems. These entropy measures are useful in estimating the heat of formation and many Physico-chemical properties. In statistical analysis of benzene structures, entropy measures showed more significant results as compared to topological indices. Therefore, we can say that the entropy measure is a newly introduced topological descriptor.


## 6. Conclusion

Using Shanon’s entropy and Chen et al. [31] entropy definitions, we generated graph entropies associated to a new information function in this research. Between indices and information entropies, a relationship is created. Using the line graph of the subdivision of these graphs, we estimated the entropies for triangular benzenoids Tx, hexagonal parallelogram Hx,y nanotubes, and ZCSx,y,z. Thermodynamic entropy of enzyme-substrate complexions [57, 58] and configuration entropy of glass-forming liquids [56] are two examples of thermodynamic entropy employed in molecular dynamics studies of complex chemical systems. Similarly, using information entropy as a crucial structural criterion could be a new step in this direction.



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*Source: 2006574-2022-10-06.xml*