Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518, Budapest 112, Hungary.
J Phys Chem A. 2013 Aug 15;117(32):7195-206. doi: 10.1021/jp4010696. Epub 2013 Jun 6.
The main motivation for this work is the exploration of rotational–vibrational states corresponding to electronic excitations in a pre-Born–Oppenheimer quantum theory of molecules. These states are often embedded in the continuum of the lower-lying dissociation channel of the same symmetry and thus are thought to be resonances. To calculate rovibronic resonances, the pre-Born–Oppenheimer variational approach of [J. Chem. Phys. 2012, 137, 024104], based on the usage of explicitly correlated Gaussian functions and the global vector representation, is extended with the complex coordinate rotation method. The developed computer program is used to calculate resonance energies and widths for the three-particle positronium anion, Ps(–), and the four-particle positronium molecule, Ps(2). Furthermore, the excited bound and resonance rovibronic states of the four-particle H2 molecule are also considered. Resonance energies and widths are estimated for the lowest-energy resonances of H(2) beyond the b (3)∑(u)(+) continuum.
这项工作的主要动机是探索分子的预 Born-Oppenheimer 量子理论中对应于电子激发的转动-振动态。这些态通常嵌入相同对称性的较低离解通道的连续谱中，因此被认为是共振态。为了计算 rovibronic 共振，基于使用显式相关高斯函数和全局向量表示的 [J. Chem. Phys. 2012, 137, 024104] 的预 Born-Oppenheimer 变分方法，使用复坐标旋转方法进行了扩展。所开发的计算机程序用于计算三粒子正电子素阴离子 Ps(–)和四粒子正电子素分子 Ps(2)的共振能和宽度。此外，还考虑了四粒子 H2 分子的激发束缚和共振 rovibronic 态。估计了 H(2)的最低能量共振超过 b (3)∑(u)(+)连续谱的能量和宽度。
