Chau Foo-Tim, Mok Daniel K W, Lee Edmond P F, Dyke John M
Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong.
J Chem Phys. 2004 Jul 22;121(4):1810-23. doi: 10.1063/1.1765654.
Restricted-spin coupled-cluster single-double plus perturbative triple excitation [RCCSD(T)] potential energy functions (PEFs) were calculated for the X (2)A" and A (2)A' states of HPCl employing the augmented correlation-consistent polarized-valence-quadruple-zeta (aug-cc-pVQZ) basis set. Further geometry optimization calculations were carried out on both electronic states of HPCl at the RCCSD(T) level with all electron and quasirelativistic effective core potential basis sets of better than the aug-cc-pVQZ quality, and also including some core electrons, in order to obtain more reliable geometrical parameters and relative electronic energy of the two states. Anharmonic vibrational wave functions of the two states of HPCl and DPCl, and Franck-Condon (FC) factors of the A (2)A'-X (2)A" transition were computed employing the RCCSD(T)/aug-cc-pVQZ PEFs. Calculated FC factors with allowance for Duschinsky rotation and anharmonicity were used to simulate the single-vibronic-level (SVL) emission spectra of HPCl and DPCl reported by Brandon et al. [J. Chem. Phys. 119, 2037 (2003)] and the chemiluminescence spectrum reported by Bramwell et al. [Chem. Phys. Lett. 331, 483 (2000)]. Comparison between simulated and observed SVL emission spectra gives the experimentally derived equilibrium geometry of the A (2)A' state of HPCl of r(e)(PCl) = 2.0035 +/- 0.0015 A, theta(e) = 116.08 +/- 0.60 degrees, and r(e)(HP) = 1.4063+/-0.0015 A via the iterative Franck-Condon analysis procedure. Comparison between simulated and observed chemiluminescence spectra confirms that the vibrational population distribution of the A (2)A' state of HPCl is non-Boltzmann, as proposed by Baraille et al. [Chem. Phys. 289, 263 (2003)].
采用增强相关一致极化价四重zeta（aug-cc-pVQZ）基组，计算了HPCl的X（²A″）和A（²A′）态的受限自旋耦合簇单双加微扰三重激发[RCCSD(T)]势能函数（PEF）。在RCCSD(T)水平上，使用优于aug-cc-pVQZ质量的全电子和准相对论有效核势基组，对HPCl的两个电子态进行了进一步的几何优化计算，其中还包括一些内层电子，以获得这两个态更可靠的几何参数和相对电子能量。利用RCCSD(T)/aug-cc-pVQZ PEF计算了HPCl和DPCl两个态的非谐振动波函数以及A（²A′）-X（²A″）跃迁的弗兰克-康登（FC）因子。考虑杜什金斯基转动和非谐性的计算FC因子用于模拟Brandon等人[《化学物理杂志》119, 2037 (2003)]报道的HPCl和DPCl的单振子能级（SVL）发射光谱以及Bramwell等人[《化学物理快报》331, 483 (2000)]报道的化学发光光谱。通过迭代弗兰克-康登分析程序，模拟和观测的SVL发射光谱之间的比较给出了实验推导的HPCl的A（²A′）态的平衡几何结构，r(e)(PCl)=2.0035±0.0015 Å，θ(e)=116.08±0.60°，以及r(e)(HP)=1.4063±0.0015 Å。模拟和观测的化学发光光谱之间的比较证实了HPCl的A（²A′）态的振动布居分布是非玻尔兹曼分布，正如Baraille等人[《化学物理》289, 263 (2003)]所提出的那样。
