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Fisher Information for a System of a Combination of Similar Potential Models

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Abstract
The solutions of the radial Schrödinger equation for a pseudoharmonic potential and Kratzer potentials has been studied separately in the past. The Kratzer potential despite different reports, the basic theoretic quantity such as Fisher information has not been reported. In this study, the solution of the radial Schrödinger equation for the combination of the pseudoharmonic and Kratzer potentials in the presence of a constant-dependent potential is obtained using the concepts and formalism of the supersymmetric and shape invariance approach. The position expectation value and momentum expectation value are calculated employing the Hellmann-Feynman Theory. The expectation values are used to calculate the Fisher information for both the position and momentum spaces in both the absence and presence of the constant-dependent potential. The obtained results revealed that the presence of the constant-dependent potential leads to an increase in the energy eigenvalue, as well as in the position and momentum expectation values. The presence of the constant-dependent potential also increases the Fisher information for both position and momentum spaces. Furthermore, the product of the position expectation value and the momentum expectation value along with the product of the Fisher information, satisfies both the Fisher’s inequality and the Cramer-Rao’s inequality.
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Subject: Physical Sciences  -   Mathematical Physics

1. Introduction

The utility of potential systems in quantum mechanics spans a wide spectrum, encompassing solutions for both bound states and scattering states, as well as various theoretical quantities such as Fisher information, Shannon entropy, variance, Tsalis entropy, Rẻnyi entropy and information energy. Diverse physical potential models have been employed to derive energy spectra for different systems, resulting in varying outcomes. For instance, when considering the sodium dimer, the energy predictions from the Yukawa potential differs from those generated by the Woods-Saxon potential. Such discrepancies arise due to the distinct physical natures and parameterization of these potential models. In the realm of quantum systems, atomic interactions are often modeled using potential energy functions, which greatly influence the properties exhibited by different systems. These potential functions, particularly those falling within the class of exponential-type potential models, effectively describe diatomic molecules and provide numerical values that align with observed data. Many of these energy potential functions have been adapted for suitability by Jia et al. [1] and are commonly explored through appropriate approximation schemes. This exploration has piqued the interest of numerous authors and researchers, particularly in nonrelativistic quantum mechanics, where the ro-vibrational spectra of diverse quantum systems have been extensively studied [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17]. For instance, Njoku et al [18] studied the Hua potential model under the nonrelativistic system. These authors obtained the bound state solutions of the Schrödinger equation for the Hua potential model. The authors numerically examined the effect of the equilibrium bond length on the energy eigenvalue for different quantum states. They further extended their study to the calculation of the thermodynamic properties. The effects of the maximum quantum state as well as the effect of the temperature parameter on the partition function and other thermodynamic properties such as the mean energy, the specific heat capacity, the entropy and the free mean energy were fully obtained. Yașuk et al. [19] studied Schrödinger equation for a non-central potential system. The applied non-central potential model is a combination of both the radial potential and angular potential models. Using the method of separation of variables, these authors calculated the energy equation and the wave function of the system via the Nikiforov-Uvarov method. They obtained the special cases of the non-central potential as the Coulomb and Hartmann ring-shaped potentials and compared the results with those of the existing literature. In ref. [20], Okon et al. studied the solutions of the Schrödinger equation for a combination of the Hulthẻn and an exponential Coulomb like potential model using parametric Nikiforov-Uvarov method. They examined the behavior of the energy of the combined potential as well as the subset potential for various quantum states and the angular momentum quantum state. The energy of the Hulthẻn potential rises as the quantum state increases. Similarly, the energy rises as the screening parameter increases for the same Hulthẻn potential. Yahya and Issa [21] obtained the solutions of the Schrödinger equation for improved Tietz potential and improved Rosen-Morse potential model using the methodology of parametric Nikiforov-Uvarov method. They studied the energy eigenvalue and the wave functions of the two potentials separately. These authors examined the relationship between the energy and the deformed parameter. They also examined the effect of the angular momentum number on the energy of the improved Rosen-Morse potential model at different quantum numbers.
However, there exists another category of potential models tailored to investigate bound state problems and related quantum systems that are not in the exponential form or Pὂschl-Teller form. Notably, among these models are the pseudoharmonic potential and the Kratzer potential. The pseudoharmonic potential integrates elements of the harmonic potential model, the inverse potential system, and a constant term, thereby capable of reproducing solutions from these three distinct potential models. Unlike many other models, the physical nature of the pseudoharmonic potential discourages the application of approximation schemes. Proposed by Davidson [22], the pseudoharmonic potential was specifically devised to elucidate the roto-vibrational states of diatomic molecules. On the other hand, the Kratzer potential serves as a molecular potential to elucidate molecular structure and atomic interactions. Its widespread application has primarily centered around bound states within the molecular domain. Because of the applications of these potentials, several authors have reported the potentials separately in Physics. Among the reports on the pseudoharmonic potential and the Kratzer potential are the work of Oyewumi and Sen [23] who studied the pure pseudoharmonic potential in the context of bound states and applied their study to diatomic molecules. In ref. [24], Oyewumi et al. studied D-dimensional system of pseudoharmonic potential and construct the Ladder operators. Sever et al. [25], obtained energy spectra for the pseudoharmonic potential and generate numerical values for some molecules with the first six quantum states. Ikhdair and Sever [26] in their study, calculated the exact polynomial eigensolutions of the Schrödinger equation for the pseudohamonic potential. In the study, they, exact bound-state energy eigenvalues and the corresponding eigenfunctions are analytically calculated. The energy states for several diatomic molecular systems are calculated numerically for various principal and angular quantum numbers. By a proper transformation, the problem was also solved and make very simple using the known eigensolutions of anharmonic oscillator potential. Das and Arda [27] in one of the articles studied, deduced the exact analytical solution of the 𝑁-Dimensional radial Schrödinger equation with pseudoharmonic potential via Laplace transform approach. The authors examined the variation of the spatial dimensions against the energy of the system. Recently, the exact solutions of κ-dependent Schrödinger equation with quantum pseudoharmonic oscillator and its applications to the thermodynamic properties in normal and superstatistics was obtained by Okorie et al. [28]. The pseudoharmonic potential is generally used to describe the roto-vibrational states of diatomic molecules, nuclear rotations and vibrations. The Kratzer potential also received different reports in the non-relativistic models. Some of the reports on the Kratzer potential includes the work of Bayrak et al. [29] who studied the radial Schrödinger equation with the Kratzer potential and obtained the exact analytical solutions to the Kratzer potential by the asymptotic iteration method. They generated numerical values for some molecules using their spectroscopic constants. Despite the extensive reporting on the Kratzer potential, its utilization concerning Fisher information remains underexplored to the best of our understanding. Motivated by the interest in Fisher information for non-exponential-type potentials, the current study aims to scrutinize the applicability of Fisher information in a scenario involving a combination of the pseudoharmonic potential and the Kratzer potential, alongside a constant-dependent potential. The Fisher information for the combination of these potential, will be obtained using expectation values. The specific form of the potential model under investigation is physically represented as [22].
V 1 ( r ) = D e ( r r e r e r ) 2 ,
while the Kratzer potential is given as [30]
V 2 ( r ) = D e ( 2 r e r r e 2 r 2 ) ,
where D e is a dissociation energy and r e is an equilibrium bond separation. These two potentials fall to the form of molecular potential because they possessed the parameters with physical meanings. The combination of equation (1) and equation (2) with a constant dependent potential is given as
V ( r ) = [ V 1 ( r ) + V 2 ( r ) ] ( 1 + η ) .
The nonrelativistic solutions for equation (3) will be obtained using supersymmetric approach. The pseudoharmonic potential and the Kratzer potential respectively, has been reported by different authors for some models.

2. Bound State Solutions

To obtain the solutions of the redial potential system in equation (3), the radial Schrödinger equation with non-relativistic energy E n , , reduced Planck constant , reduced mass of the molecule μ , and the radial wave function R n , ( r ) is given as
2 2 μ d 2 R n , ( r ) d r 2 + ( V ( r ) + 2 2 μ 1 r 2 ) R n , ( r ) = E n , R n , ( r ) .
Substituting the radial potential system in equation (3) into equation (4), we obtain a second-order differential equation of the form
d 2 R n , ( r ) d r 2 + ( λ ( E n , 2 D e ( 1 + η ) ) + λ D e ( 1 + η ) r 2 r e 2 2 λ D e r e ( 1 + η ) r + 2 λ D e r e 2 ( 1 + η ) + ( + 1 ) r 2 ) R n , ( r ) = 0.
where λ = 2 μ 2 . The supersymmetric approach suggests the ground state wave function for the next step. Thus, the ground state wave function is written as
R 0 , ( r ) = e x p ( W ( r ) d r ) ,
where W ( r ) is referred to as superpotential function in supersymmetry quantum mechanics. The ground state wave function corresponds to the two partner Hamiltonians given as
H + = A ^ A ^ = d 2 d r 2 + V + ( r ) H = A ^ A ^ = d 2 d r 2 V ( r ) } ,
where
A ^ = d d r W ( r ) A ^ = d d r W ( r ) } .
Substituting the ground state wave function into equation (5), the resulting solution appears in a differential equation of the form
W 2 ( r ) d W ( r ) d r λ ( E 0 , 2 D e ( 1 + η ) ) + λ D e ( 1 + η ) r 2 r e 2 + 2 λ r e D e ( r e r ) ( 1 + η ) + ( + 1 ) r 2 ,
where the superpotential W ( r ) is proposed as
W ( r ) = θ 0 θ 1 r 1 .
The two terms θ 0 and θ 1 in equation (10) are constants in the proposed superpotential that will soon be determined. Substituting equation (10) into equation (9), after some mathematical manipulations and simplifications, the values of the superpotential constants in equation (10) are obtained as
θ 1 = 1 ± ( 1 + 2 ) 2 + 8 λ D e r e 2 ( 1 + η ) 2 ,
θ 0 = λ D e r e ( 1 + η ) θ 1 1 ,
θ 0 2 = λ ( E n , + 2 D e r e ( 1 + η ) ) θ 1 λ 1 D e r e 2 ( 1 + η ) .
With the aid of equations (7), (8) and (10), the partner potentials in supersymmetry quantum mechanics can be constructed as
V + ( r ) = W 2 ( r ) + d W ( r ) d r = θ 0 2 2 θ 0 θ 1 r + θ 1 ( θ 1 1 ) r 2 ,
V ( r ) = W 2 ( r ) d W ( r ) d r = θ 0 2 2 θ 0 θ 1 r + θ 1 ( θ 1 + 1 ) r 2 .
Equations (14) and (15) are family potentials and they satisfied the shape invariance condition via mapping of the form θ 1 θ 1 + n , θ 1 = a 0 . It is deduced that a 1 = f ( a 0 ) = a 0 + 1 , where a 1 is a new set of parameters uniquely determined from the old set a 0 and R ( a 1 ) is a residual term that is independent of the variable r . Since a 1 = a 0 + 1 , and by recurrence relation, a n = a 0 + n . From the shape invariance approach, we can write [31,32,33]
R ( a 1 ) = V + ( a 0 , r ) V ( a 1 , r ) ,
R ( a 2 ) = V + ( a 1 , r ) V ( a 2 , r ) ,
R ( a 3 ) = V + ( a 2 , r ) V ( a 3 , r ) ,
R ( a n ) = V + ( a n 1 , r ) V ( a n , r ) .
The energy level can be obtained using
E n , = κ = 1 n R ( a κ ) = R ( a 1 ) + R ( a 2 ) + R ( a 3 ) .... + R ( a n ) .
From equation (20), we obtain the complete energy eigenvalue equation as
E n , = 2 μ 2 D e 2 r e 2 ( 1 + η ) 2 2 ( n + 1 2 + 1 2 Λ ) 2 + 2 μ μ D e ( 1 + η ) 2 r e 2 ( 2 n + 1 + 1 2 Λ ) 2 D e ,
Λ = ( 1 + 2 ) 2 + 8 λ D e r e 2 ( 1 + η ) .

3. Calculation of Expectation Values

Here we calculate the position and momentum expectation values using Hellmann Feynman Theorem. The Hellmann-Feynman Theorem relates the derivative of the total energy with respect to a parameter and to the expectation value of the derivative of the Hamiltonian by the same parameter [34,35,36,37]. If the spatial distribution of the electrons is determined by the solution of the Schrödinger equation, then, the forces in the system can be calculated using classical electrodynamics. If the Hamiltonian H for a particular system is a function of some parameters v with the eigenvalue and eigenfunctions denoted by E n , ( v ) and R n , ( v ) respectively, then, we can find the various expectation values provided the associated normalized eigenfunction R n , ( v ) is continuous with respect to the parameter v . Then
E n , ( v ) v = R n , ( v ) | H ( v ) v | R n , ( v ) .
and
H = 2 2 μ d 2 d r 2 + 2 2 μ ( + 1 ) r 2 + D e ( r r e r e r ) 2 D e ( 2 r e r r e 2 r ) .
The various expectation values can now be calculated.
(I): Expectation value r 2 . To obtain the expectation value of r 2 , we set v = D e , then
r 2 = 2 μ Λ ( Λ 2 2 μ 4 μ 2 D e 2 r e 2 ( 1 + η ) 2 2 Λ 0 3 ) .
(II): Expectation value p 2 . Setting v = μ , we have the expectation value
p 2 = 4 μ 3 D e 2 r e 2 ( 1 + η ) 2 2 Λ 0 2 ( 1 μ 2 4 D e r e 2 ( 1 + η ) Λ Λ 0 2 ) + 2 D e ( 1 + η ) μ ( 2 Λ 1 Λ 2 r e 2 + 4 Λ 2 r e 2 Λ ) Λ 1 Λ 2 2 μ 2 .

4. Fisher Information.

Fisher information is a concept in information theory that measures the amount of information that is available in a given system. In a quantum system, Fisher information is a probabilistic measure of uncertainty in a system. Thus, for quantum mechanical systems, the Fisher information-based uncertainty relation has been used as an alternative to the Heisenberg uncertainty relation (HUR). Therefore, for a system with physical parameters θ and ρ ( r , θ ) , [38,39] then,
d r ρ ( r , θ ) = 1 ,
where ρ ( r , θ ) accounts for the details of the probability density. The Fisher information is examined in two different parts. These are Fisher information in the position space and Fisher information in the momentum space. The Fisher information for both the position space and momentum space can be written as
I ( ρ ) = 0 1 ρ ( r ) [ d ρ ( r ) d r ] 2 d r , I ( γ ) = 0 1 γ ( p ) [ d γ ( p ) d p ] 2 d p , } ,
where ρ ( r ) is the probability density for the position space and ρ ( r ) is the probability density for the momentum space. The implication of equation (28) is that a concentrated density gives a higher quantity that provides a local change in the density where the system can be better described in an information-theoretic manner. In terms of the expectation values, the Fisher information for both the position space and the momentum space can therefore be written as [40,41,42]
I ( ρ ) = 4 p 2 2 ( 2 L + 1 ) | m | r 2 , I ( γ ) = 4 r 2 2 ( 2 L + 1 ) | m | p 2 } ,
where L is the total angular momentum and m is the magnetic quantum number. In the absence of the magnetic quantum number m , the terms after the minus sign of equation (29) vanishes and then, the Fisher information for the position space and the Fisher information for the momentum space in equation (29) can be written in the form
I ( ρ ) = 4 p 2 , I ( γ ) = 4 r 2 } .
To check the validity of the product of expectation values as a Cramer-Rao inequality, Dehesa et al. [41], give the following conditions
p 2 ( L + 1 2 ) 2 r 2 , r 2 ( L + 1 2 ) p 2 } .
This implies that
I ( ρ ) 4 ( 1 2 | m | 2 L + 1 ) p 2 , I ( γ ) 4 ( 1 2 | m | 2 L + 1 ) r 2 } .
When m = 0 , the product of equation (32) can be written as
I ( ρ ) I ( γ ) 16 p 2 r 2 .
The minimum bound for the Fisher product [43] is given by
I ( ρ ) I ( γ ) 36.
Using equations (21) and (34), the minimum bound the product of the position and momentum expectation becomes
p 2 r 2 9 4 .
Substituting equations (25) and (26) into (30), the Fisher information for the position space and the momentum space respectively becomes
I ρ = 16 μ 3 D e 2 r e 2 ( 1 + η ) 2 2 Λ 0 2 ( 1 μ 2 4 D e r e 2 ( 1 + η ) Λ Λ 0 2 ) + 4 2 D e ( 1 + η ) μ ( 2 Λ 1 Λ 2 r e 2 + 4 Λ 2 r e 2 Λ ) 4 2 Λ 1 Λ 2 μ 2 .
I γ = 8 μ Λ ( Λ 2 2 μ 4 μ 2 D e 2 r e 2 ( 1 + η ) 2 2 Λ 0 3 ) .

5. Discussion

Table 1 presents the energy eigenvalues of the combination of pseudoharmonic potential and the Kratzer potential for various quantum number and angular momentum in the absence and presence of the constant dependent potential for two different values of the dissociation energy. The energy of the combined potentials responded positively to an increase in each of the dissociation energy, quantum number, angular momentum and constant dependent potential. This implies that an increase in any of dissociation energy, quantum number, angular momentum and constant dependent potential, increases the energy of the interacting potential system. From Table 1, it is also noted that as the angular momentum increases, the energy difference between the successive one angular momentum and the next angular momentum also increases. In Table 2, the energy of the combination of the pseudoharmonic potential and the Kratzer potential for various quantum number and equilibrium bond length in the absence and presence of the constant dependent potential is presented. The numerical values in Table 2 showed that the equilibrium bond length varies inversely with the energy of the interacting potential. However, the quantum number and the angular momentum respectively varies directly with the energy of the system. In Table 3. We presented the energy eigenvalue of the interacting potential for various dissociation energy and constant dependent potential at the ground state and the first excited state. The energy of the combined potential model increases as each of the dissociation energy and the constant dependent potential respectively increases. The energy of the system also increases as the quantum number and the angular momentum respectively increases.
The numerical values for the Fisher information in position space and momentum space as well as their product in the absence and presence of the constant-dependent potential are presented in Table 4 and Table 5. In Table 4, the Fisher information in position space and the quantum number varies inversely with each other but the Fisher information in momentum space varies directly with the quantum number. The Fisher information both in position space and in momentum space in the presence of the constant dependent potential are higher than their counterpart produced in the absence of the constant dependent potential. The minimum bound for the Fisher product in the absence of constant dependent potential is 111.4298232 while in the presence of the constant dependent potential, the minimum bound is 339.29054. These values are above the standard value of 36. Thus, the result in Table 4 satisfied the Fisher inequality given in equation (34). The variation of the Fisher information showed that a decrease in the Fisher information in position space corresponds to an increase in Fisher information in momentum space. This implies that a diffused density distribution in the configuration space is associated with a localized density distribution in the momentum space. In Table 5, the Fisher information in position space and in momentum space for various values of the equilibrium bond separation are presented in the absence and presence of the constant dependent potential. In this Table, the Fisher information in position space varies directly with the equilibrium bond separation both in the presence and absence of the constant-dependent potential. However, in the momentum space, the Fisher information varies indirectly with the equilibrium bond separation. The minimum bound for the Fisher product in the absence of constant dependent potential is 51.4913757 while in the presence of the constant dependent potential is 212.949992. The values of the minimum bound also confirmed that the results in Table 5 satisfied the Fisher inequality. The result shows that a diffused density in the configuration space corresponds to the localized density in the momentum space. The variation of the Fisher information against the quantum state in Table 4 is contrary to the variation of Fisher information against the equilibrium bond separation in Table 5, but satisfied the Fisher inequality in both cases. In Table 5, a strongly localized distribution in the momentum space corresponds to widely delocalized distribution in the position space. The results obtained obeyed Heisenberg Uncertainty Principle. The position and momentum expectation values and their product for various values of the angular momentum number are presented in Table 6 for the absence and presence of the constant dependent potential. It is noted that as the position space expectation value varies directly with the angular momentum, the momentum space expectation value varies inversely with the angular momentum number. As observed in Table 4, Table 5 and Table 6, the results with the constant dependent potential are higher than the results without constant dependent potential. The product of the expectation values for the presence and absence of the constant dependent potential are greater than the standard value of 2.25. The minimum bound for the product of the expectation values in the absence and presence of the constant dependent potential are 3.9027949 and 12.1497115 respectively. These results satisfied Cramer Rao's inequality for the product of expectation. Table 7 presents Fisher information for both the position space and momentum space and their product in the absence and presence of constant dependent potential for various angular momentum. The Fisher information for the position space in both the absence and presence of constant dependent potential respectively increases as the angular momentum increases. However, the Fisher information for the momentum space in the absence and presence of constant dependent potential respectively, decreases as the angular momentum increases. The product of the Fisher information satisfied the Cramer-Rao inequality but decreases with increase in the angular momentum.

6. Conclusion

The solutions of the combination of pseudoharmonic potential and Kratzer potential was obtained and the effects of the potential parameters on the energy, the expectation values and the Fisher information were all observed. It was shown that the presence of constant dependent potential, the dissociation energy, the quantum number and the angular momentum respectively increases the energy eigenvalue of the system but the equilibrium bond length reduces the energy. It was noticed that the variation of the quantum number against the Fisher information is contrary to the variation of the equilibrium bond length against the Fisher information. The constant dependent potential increases the position expectation value but decreases the momentum expectation value. It is discovered that some parameters increase the Fisher information in position space and decrease Fisher information in momentum space while some parameters decrease the Fisher information in position space and increase the Fisher information in momentum space. The effect of the potential parameters on the energy and Fisher information in the absence of the constant dependent potential is the same as in the presence of the of the constant dependent potential. The presence of the constant dependent potential only increases the quantity studied.

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Table 1. Energy eigenvalue for various quantum states and angular momentum with μ = = 1 , and r e = 0.25 , in the absence and presence of constant-dependent potential for two values of the dissociation energy.
Table 1. Energy eigenvalue for various quantum states and angular momentum with μ = = 1 , and r e = 0.25 , in the absence and presence of constant-dependent potential for two values of the dissociation energy.
n η = 0 η = 0.5
D e = 5 D e = 10 D e = 5 D e = 10
0



1



2



3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
19.1915543
26.8693976
37.5880690
49.3042587
43.8601841
51.8866789
62.7622893
74.5398554
68.9627325
77.0734494
88.0004415
99.8033288
94.1756967
102.316428
113.265083
125.080290
30.2367130
38.6168018
51.8488919
67.2542617
64.5835661
73.5761120
87.2096164
102.806150
99.8304090
109.000745
122.777346
138.455898
135.354381
144.594507
158.434548
174.154043
29.9096370
38.0538010
50.2771052
64.1033929
59.8627152
68.5040080
81.0061110
94.9538017
90.4917350
99.2664182
111.864086
125.862895
121.312779
130.137638
142.776689
156.800703
50.2267069
58.8074820
73.2878939
90.9334004
91.8404299
101.195400
116.302626
134.292068
134.751205
144.358222
159.703767
177.845801
178.109873
187.822519
203.277995
221.497925
Table 2. Energy eigenvalue for various quantum states and equilibrium bond length with μ = = 1 , and D e = 5 , in the absence and presence of constant-dependent potential for s wave and wave.
Table 2. Energy eigenvalue for various quantum states and equilibrium bond length with μ = = 1 , and D e = 5 , in the absence and presence of constant-dependent potential for s wave and wave.
n r e η = 0 η = 0.5
= 0 = 1 = 0 = 1
0



1



2



3



4



5
0.5
1.0
1.5
2.0
0.5
1.0
1.5
2.0
0.5
1.0
1.5
2.0
0.5
1.0
1.5
2.0
0.5
1.0
1.5
2.0
0.5
1.0
1.5
2.0
12.4202881
9.39252710
8.44361600
7.98103440
24.3346767
15.1059713
12.1681436
10.7362083
36.6586629
21.0620459
16.0437357
13.5932412
49.1359643
27.1474431
20.0143131
16.5207835
61.6833974
33.3080324
24.0475954
19.4986801
74.2674019
39.5153037
28.1239350
22.5134945
14.5803237
9.91579930
8.66857060
8.10491030
26.7141787
15.6968954
12.4202881
10.8734364
39.1157627
21.6877923
16.3126127
13.7395803
51.6272352
27.7929105
20.2940459
16.6735512
64.1920084
33.9654942
24.3346767
19.6561126
76.7857329
40.1804755
28.4161668
22.6743939
21.9178843
18.2993918
17.1549376
36.3343188
25.2162768
21.6715263
19.9405623
16.5947227
51.3010558
32.4241376
26.3605159
23.3994205
66.4978821
39.8011807
31.1657135
26.9411554
81.8076698
47.2832585
36.0520860
30.5450424
97.1793420
54.8339773
40.9968719
34.1964520
24.0760055
18.8139539
17.3764753
16.7170015
38.7409248
25.7961769
21.9178843
20.0746906
53.8062866
33.0409857
26.6233344
23.5421470
69.0498216
40.4404751
31.4398758
27.0902716
84.3845319
47.9369683
36.3343188
30.6990056
99.7706981
55.4973648
41.2850021
34.3541585
Table 3. Energy eigenvalue for various values dissociation energy and constant dependent potential with μ = = 1 , and r e = 0.25 , at the ground state and first excited state.
Table 3. Energy eigenvalue for various values dissociation energy and constant dependent potential with μ = = 1 , and r e = 0.25 , at the ground state and first excited state.
D e η n = 0 n = 1
= 0 = 1 = 0 = 1
1





2





3





4





5




0
1
2
3
4
5
0
1
2
3
4
5
0
1
2
3
4
5
0
1
2
3
4
5
0
1
2
3
4
5
4.18168780
8.50000000
12.5793525
16.5379816
20.4202881
24.2487113
6.50000000
14.5379816
22.2487113
29.7921099
37.2291330
44.5908154
8.57935250
20.2487113
31.5215665
42.5908154
53.5303880
64.3780215
10.5379816
25.7921099
40.5908154
55.1551611
69.5701085
83.8790804
12.4202881
31.2291330
49.5303880
67.5701085
85.4430187
103.197567
6.0217369
10.5510171
14.7015198
18.6878788
22.5803237
26.4107479
8.55101710
16.6878788
24.4107479
31.9479971
39.3742236
46.7242693
10.7015198
22.4107479
33.6722999
44.7242693
55.6472139
66.4800000
12.6878788
27.9479971
42.7242693
57.2668299
71.6631972
85.9565223
14.5803237
33.3742236
51.6472139
69.6631972
87.5169397
105.255816
9.72050810
16.2222222
21.9412282
27.2631497
32.3346767
37.2301178
14.2222222
25.2631497
35.2301178
44.6521671
53.7304216
62.5667333
17.9412282
33.2301178
47.2265378
60.5667333
73.4925650
86.1265502
21.2631497
40.6521671
58.5667333
75.7320533
92.4238854
108.781987
24.3346767
47.7304216
69.4925650
90.4238854
110.829779
130.865107
11.6301374
18.4038820
24.2349788
29.6126984
34.7141787
39.6259364
16.4038820
27.6126984
37.6259364
47.0601538
56.1377674
64.9679851
20.2349788
35.6259364
49.6351901
62.9679851
75.8806382
88.5000000
23.6126984
43.0601538
60.9679851
78.1153066
94.7875816
111.126964
26.7141787
50.1377674
71.8806382
92.7875816
113.170292
133.184707
Table 4. Fisher information for position space and momentum space in the absence and presence of constant dependent potential for various quantum states and the Fisher product with μ = = = 1 ,   r e = 0.5 , and D e = 2.5 .
Table 4. Fisher information for position space and momentum space in the absence and presence of constant dependent potential for various quantum states and the Fisher product with μ = = = 1 ,   r e = 0.5 , and D e = 2.5 .
n η = 0 η = 0.5
I ρ I γ I ρ I γ I ρ I γ I ρ I γ
0
1
2
3
4
5
6
7
8
8
10
11
12
13
14
15
12.9965839
11.8185475
11.2615469
10.9565616
10.7720175
10.6520394
10.5697147
10.5108053
10.4672122
10.4340553
10.4082527
10.3877810
10.3712673
10.3577538
10.3465556
10.3371727
8.5737778
15.2579808
22.1905981
29.2240214
36.3056214
43.4130476
50.5355353
57.6673891
64.8053694
71.9475241
79.0926206
86.2398494
93.3886615
100.538674
107.689612
114.841276
111.4298232
180.3271707
249.9004614
320.1947901
391.0847898
462.4374938
534.1461897
606.1306983
678.3315540
750.7044447
823.2159806
895.8406674
968.5587745
1041.354832
1114.216560
1187.134100
21.5583462
19.6777166
18.7115540
18.1551929
17.8069278
17.5749107
17.4127458
17.2950190
17.2068853
17.1392093
17.0861231
17.0437192
17.0093145
16.9810180
16.9574657
16.9376539
15.7382452
23.7495543
32.1266502
40.6676667
49.2919216
57.9626756
66.6613706
75.3778408
84.1061482
92.8426388
101.584965
110.331565
119.081364
127.833606
136.587746
145.343382
339.2905400
467.3369980
601.1395518
738.3293339
877.7376907
1018.688851
1160.757499
1303.661192
1447.204844
1591.249420
1735.693225
1880.460203
2025.492369
2170.744768
2316.182020
2461.775909
Table 5. Fisher information for position space and momentum space at the ground state for various equilibrium bond separation and the Fisher product in the absence and presence of constant dependent potential with μ = = = 1 , and D e = 2.5 .
Table 5. Fisher information for position space and momentum space at the ground state for various equilibrium bond separation and the Fisher product in the absence and presence of constant dependent potential with μ = = = 1 , and D e = 2.5 .
r e η = 0 η = 0.5
I ρ I γ I ρ I γ I ρ I γ I ρ I γ
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
6.3749475
12.0910640
14.6231981
16.0247585
16.9078176
17.5129218
17.9525752
18.2860804
18.5475457
18.7579355
18.9308264
19.0753897
19.1980391
19.3033929
19.3948598
19.4750097
19.5458162
6.7680001
6.2814977
6.0423780
5.8983477
5.8018537
5.7326651
5.6806283
5.6400719
5.6075771
5.5809594
5.5587579
5.5399585
5.5238356
5.5098559
5.4976189
5.4868181
5.4772149
43.1456451
75.9499903
88.3588904
94.5195968
98.0966833
100.395716
101.981906
103.134809
104.006792
104.687276
105.231880
105.676868
106.046812
106.358913
106.625548
106.855836
107.056635
13.9837226
20.5118296
23.4211406
25.0442629
26.0739294
26.7834340
27.3012806
27.6955632
28.0056349
28.2557876
28.4618122
28.6344110
28.7810910
28.9072717
29.0169624
29.1131925
29.1982930
13.7463577
13.1590415
12.8653865
12.6881230
12.5694080
12.4843480
12.4204164
12.3706163
12.3307320
12.2980723
12.2708384
12.2477829
12.2280132
12.2108738
12.1958730
12.1826340
12.1708638
192.2252527
269.9160160
301.3220276
317.7646874
327.7338557
334.3737107
339.0932721
342.6111838
345.3299783
347.4917179
349.2502995
350.7080500
351.9355594
352.9830473
353.8871873
354.6753683
355.3684483
Table 6. Position expectation value and momentum expectation value at the ground state for various angular momentum quantum state and their product in the absence and presence of constant dependent potential with μ = = 1 ,   r e = 0.5 , and D e = 2.5 in the absence and presence of the constant dependent potential.
Table 6. Position expectation value and momentum expectation value at the ground state for various angular momentum quantum state and their product in the absence and presence of constant dependent potential with μ = = 1 ,   r e = 0.5 , and D e = 2.5 in the absence and presence of the constant dependent potential.
η = 0 η = 0.5
r 2 p 2 r 2 p 2 r 2 p 2 r 2 p 2
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
2.0753109
2.1434445
2.4796239
3.0345051
3.7149293
4.4660484
5.2591091
6.0785638
6.9155189
7.7645982
8.6223893
9.4866342
10.355785
11.228746
12.104725
12.983131
4.2441101
3.2491460
2.3486134
1.7624127
1.3858907
1.1325692
0.9534294
0.8212049
0.7201144
0.6405721
0.5764852
0.5238228
0.4798244
0.4425416
0.4105633
0.3828440
8.8078482
6.9643639
5.8236779
5.3480505
5.1484858
5.0581087
5.0141894
4.9917465
4.9799647
4.9737848
4.9706794
4.9693156
4.9689582
4.9691872
4.9697553
4.9705140
3.9027949
3.9345613
4.2100767
4.7530480
5.4798280
6.3206480
7.2328358
8.1913537
9.1811818
10.192968
11.220659
12.260199
13.308778
14.364399
15.425605
16.491312
6.5411490
5.3895866
4.1263248
3.1895560
2.5445494
2.0942879
1.7693011
1.5265679
1.3396688
1.1919700
1.0726518
0.9744445
0.8923155
0.8226858
0.7629492
0.7111670
25.5287631
21.2056588
17.3721438
15.1601125
13.9436929
13.2372565
12.7970647
12.5046576
12.2997429
12.1497115
12.0358600
11.9468833
11.8756286
11.8173877
11.7689537
11.7280766
Table 7. Fisher information for both position space momentum space at the ground state for various angular momentum quantum state and their product with μ = = 1 ,   r e = 0.5 , and D e = 2.5 in the absence and presence of the constant dependent potential.
Table 7. Fisher information for both position space momentum space at the ground state for various angular momentum quantum state and their product with μ = = 1 ,   r e = 0.5 , and D e = 2.5 in the absence and presence of the constant dependent potential.
η = 0 η = 0.5
I ( ρ ) I ( γ ) I ( ρ ) I ( γ ) I ( ρ ) I ( γ ) I ( ρ ) I ( γ )
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
8.30124380
8.57377780
9.91849550
12.1380204
14.8597170
17.8641936
21.0364363
24.3142550
27.6620757
31.0583928
34.4895572
37.9465368
41.4231385
44.9149846
48.4188988
51.9325232
16.976441
12.996584
9.3944536
7.0496510
5.5435626
4.5302766
3.8137178
3.2848197
2.8804576
2.5622883
2.3059406
2.0952913
1.9192976
1.7701664
1.6422531
1.5313761
140.925571
111.429823
93.1788457
85.5688076
82.3757720
80.9297386
80.2270307
79.8679439
79.6794347
79.5805565
79.5308712
79.5090499
79.5033319
79.5069946
79.5160843
79.5282236
15.6111797
15.7382452
16.8403066
19.0121919
21.9193120
25.2825921
28.9313433
32.7654146
36.7247270
40.7718702
44.8826362
49.0407939
53.2351111
57.4575959
61.7024212
65.9652465
26.1645959
21.5583462
16.5052993
12.7582239
10.1781975
8.37715150
7.07720460
6.10627160
5.35867530
4.76788000
4.29060710
3.89777810
3.56926200
3.29074340
3.05179690
2.84466800
408.4602096
339.2905400
277.9543004
242.5618001
223.0990871
211.7961041
204.7530351
200.0745216
196.7958870
194.3953836
192.5737593
191.1501323
190.0100570
189.0782028
188.3032599
187.6492262
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