Richter Falk, Carbonnière P
Groupe de Chimie Théorique et Réactivité IPREM-ECP, Université de Pau et des Pays de l'Adour, Pau, France.
J Chem Phys. 2022 Feb 28;156(8):084306. doi: 10.1063/5.0081289.
A valence coordinate HNOH ground state potential energy surface accurate for all levels up to 6000 cm relative to trans zero point energy has been generated at the coupled-cluster single double triple-F12/aug-cc-pVTZ level encompassing the trans and cis as well as the N-H permutational conformers. All cis and trans fundamentals and a complete set of eigenfunctions up to about 3100 cm have been calculated and assigned using the improved relaxation method of the Heidelberg multi-configuration time-dependent Hartree package and an exact expression for the kinetic energy in valence coordinates generated by the TANA program. The average and maximal error to all observed transitions is about 6.3 and 14.6 cm, respectively. Local cis eigenfunctions exist with up to two quanta in the isomerization mode ν. Although no significant inversion splittings have been found up to the considered 3100 cm, they are expected within the fundamental energy range in view of the calculated 4261 cm H permutation/inversion barrier height. The cis-NH symmetric stretch fundamental shows a Fermi resonance with a splitting of about 10 cm.
已在耦合簇单双三重态 - F12/aug - cc - pVTZ 水平上生成了相对于反式零点能所有能级高达 6000 cm⁻¹ 准确的价坐标 HNOH 基态势能面，涵盖反式和顺式以及 N - H 排列异构体。使用海德堡多组态含时 Hartree 程序包的改进弛豫方法以及 TANA 程序生成的价坐标中动能的精确表达式，计算并指定了所有顺式和反式基频以及高达约 3100 cm⁻¹ 的一组完整本征函数。对所有观测到的跃迁的平均误差和最大误差分别约为 6.3 cm⁻¹ 和 14.6 cm⁻¹。在异构化模式 ν 中存在多达两个量子的局部顺式本征函数。尽管在高达所考虑的 3100 cm⁻¹ 范围内未发现明显的反转分裂，但鉴于计算出的 4261 cm⁻¹ 的 H排列/反转势垒高度，预计在基频能量范围内会出现。顺式 - NH 对称伸缩基频显示出约 10 cm⁻¹ 分裂的费米共振。
