Tecmer Paweł, Boguslawski Katharina, Johnson Paul A, Limacher Peter A, Chan Matthew, Verstraelen Toon, Ayers Paul W
Department of Chemistry and Chemical Biology, McMaster University , 1280 Main Street West, L8S 4M1, Hamilton, Ontario, Canada.
J Phys Chem A. 2014 Oct 2;118(39):9058-68. doi: 10.1021/jp502127v. Epub 2014 Apr 30.
We present a systematic theoretical study on the dissociation of diatomic molecules and their spectroscopic constants using our recently presented geminal-based wave function ansätze. Specifically, the performance of the antisymmetric product of rank two geminals (APr2G), the antisymmetric product of 1-reference-orbital geminals (AP1roG) and its orbital-optimized variant (OO-AP1roG) are assessed against standard quantum chemistry methods. Our study indicates that these new geminal-based approaches provide a cheap, robust, and accurate alternative for the description of bond-breaking processes in closed-shell systems requiring only mean-field-like computational cost. In particular, the spectroscopic constants obtained from OO-AP1roG are in very good agreement with reference theoretical and experimental data.
我们使用我们最近提出的基于双电子对的波函数近似，对双原子分子的解离及其光谱常数进行了系统的理论研究。具体而言，针对标准量子化学方法，评估了二阶双电子对反对称积（APr2G）、单参考轨道双电子对反对称积（AP1roG）及其轨道优化变体（OO - AP1roG）的性能。我们的研究表明，这些基于双电子对的新方法为描述闭壳层系统中的断键过程提供了一种廉价、稳健且准确的替代方案，仅需类似平均场的计算成本。特别是，从OO - AP1roG获得的光谱常数与参考理论和实验数据非常吻合。
