Machado Daniel F S, Silva Rodrigo A L, de Oliveira Ana Paula, Carvalho-Silva Valter H, Gargano Ricardo, Ribeiro Luciano, de Oliveira Heibbe C B
Laboratório de Estrutura Eletrônica e Dinâmica Molecular (LEEDMOL), Instituto de Química, Universidade de Brasília, CP 4478, Brasília, DF, 70919-970, Brazil.
Grupo de Química Teórica e Estrutural de Anápolis, Câmpus de Ciências Exatas de Anápolis, Universidade Estadual de Goiás, Anápolis, GO, CP 459, Brazil.
J Mol Model. 2017 Jun;23(6):182. doi: 10.1007/s00894-017-3339-3. Epub 2017 May 9.
In this paper, we propose a new alternative analytical function aiming to better describe the potential energy curves of the doubly charged diatomic molecules. To achieve this goal, we modified an existing potential function in the literature to describe dicationic diatomic molecules using the deformed exponential function. We generated the potential energy curve of the testing group of dicationic diatomic molecules [Formula: see text], BH, [Formula: see text] and NH by means of the CCSD(T)/aug-cc-pVQZ level of theory. To validate this new function, we also calculated the spectroscopic constants and the rovibrational spectra for the electronic state [Formula: see text]of the [Formula: see text] and [Formula: see text] systems using the Dunham and discrete variable representation methods. For BH and NH molecules, despite exhibiting a local minimum in the potential energy curve, no vibrational levels are supported, so the spectroscopic constants for these poorly bound systems are invalidated. The fitting accuracy had a better performance over the original potential for describing dicationic diatomic systems, considering that the discrete variable representation method resulted in a similar vibrational structure described in the literature. This fact can be explained due to the deformed function's flexibility.
在本文中，我们提出了一种新的替代分析函数，旨在更好地描述双电荷双原子分子的势能曲线。为实现这一目标，我们修改了文献中现有的一个势函数，使用变形指数函数来描述双阳离子双原子分子。我们借助CCSD(T)/aug-cc-pVQZ理论水平生成了双阳离子双原子分子测试组[化学式：见正文]、BH、[化学式：见正文]和NH的势能曲线。为验证这个新函数，我们还使用邓纳姆方法和离散变量表示法计算了[化学式：见正文]和[化学式：见正文]体系电子态[化学式：见正文]的光谱常数和振转光谱。对于BH和NH分子，尽管在势能曲线中呈现出一个局部最小值，但不存在支持的振动能级，因此这些弱束缚体系的光谱常数无效。考虑到离散变量表示法产生了与文献中描述的相似的振动结构，在描述双阳离子双原子体系时，拟合精度相对于原始势函数有更好的表现。这一事实可以归因于变形函数的灵活性。
