The Deng–Fan–Eckart potential is as good as the Morse potential in studying atomic interaction in diatomic molecules. By using the improved Pekeris-type approximation, to deal with the centrifugal term, we obtain the bound-state solutions of the radial Schrödinger equation with this adopted molecular model via the Factorization Method. With the energy equation obtained, the thermodynamic properties of some selected diatomic molecules (H 2 , CO, ScN and ScF) were obtained using Poisson summation method. The unnormalized wave function is also derived. The energy spectrum for a set of diatomic molecules for different values of the vibrational n and rotational $$\ell$$ ℓ are obtained. To show the accuracy of our results, we discuss some special cases by adjusting some potential parameters and also compute the numerical eigenvalue of the Deng–Fan potential for comparison sake. However, it was found out that our results agree excellently with the results obtained via other methods.

中文翻译：

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使用泊松求和法的 Deng-Fan-Eckart 势模型的热特性

在研究双原子分子中的原子相互作用时，Deng-Fan-Eckart 势与 Morse 势一样好。通过使用改进的Pekeris型近似，处理离心项，我们通过分解方法获得了径向薛定谔方程的束缚态解与所采用的分子模型。根据获得的能量方程，使用泊松求和方法获得了一些选定的双原子分子（H 2 、CO、ScN 和ScF）的热力学性质。还导出了未归一化的波函数。获得了一组双原子分子在振动 n 和旋转 $$\ell$$ ℓ 的不同值下的能谱。为了显示我们结果的准确性，我们通过调整一些势参数来讨论一些特殊情况，并计算Deng-Fan势的数值特征值以供比较。然而，我们发现我们的结果与通过其他方法获得的结果非常吻合。