Time-dependent quasirelativistic density-functional theory based on the zeroth-order regular approximation.
Time-dependent quasirelativistic density-functional theory based on the zeroth-order regular approximation.
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DOI：
10.1063/1.2047554
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发表时间：
2005-10
期刊：
影响因子：
--
通讯作者：
Daoling Peng;Wenli Zou;Wenjian Liu
中科院分区：
文献类型：
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作者：
Daoling Peng;Wenli Zou;Wenjian Liu
基于相对论哈密顿量的零级正则近似（ZORA）和绝热交换关联核的非共线形式，发展了含重元素体系激发能的含时准相对论密度泛函理论.为了避免规范依赖的ZORA哈密顿模型的原子势，而不是完整的分子势，被用来构建ZORA动力学算符的基态计算。因此，ZORA动力学算子不再响应响应计算中的密度变化。此外，它表明，对于封闭壳层基态，时间反演对称性可以用来简化本征值方程的近似形式，这是类似于依赖于时间的非相对论密度泛函理论。这是通过调用诱导密度矩阵的独立粒子近似来实现的。由此产生的理论被施加到调查的全球潜在的能量曲线的低LambdaS和欧米茄耦合的AuH分子的电子状态。导出的光谱参数，包括绝热和垂直激发能，平衡键长，谐波和非谐波振动常数，基频和离解能，是在与时间相关的四分量相对论密度泛函理论和从头算多参考二阶微扰理论的良好协议。尽管如此，就计算工作而言，这种含时密度泛函理论的两分量相对论版本仅比四分量相对论版本有适度的优势。
A time-dependent quasirelativistic density-functional theory for excitation energies of systems containing heavy elements is developed, which is based on the zeroth-order regular approximation (ZORA) for the relativistic Hamiltonian and a noncollinear form for the adiabatic exchange-correlation kernel. To avoid the gauge dependence of the ZORA Hamiltonian a model atomic potential, instead of the full molecular potential, is used to construct the ZORA kinetic operator in ground-state calculations. As such, the ZORA kinetic operator no longer responds to changes in the density in response calculations. In addition, it is shown that, for closed-shell ground states, time-reversal symmetry can be employed to simplify the eigenvalue equation into an approximate form that is similar to that of time-dependent nonrelativistic density-functional theory. This is achieved by invoking an independent-particle approximation for the induced density matrix. The resulting theory is applied to investigate the global potential-energy curves of low-lying LambdaS- and omega omega-coupled electronic states of the AuH molecule. The derived spectroscopic parameters, including the adiabatic and vertical excitation energies, equilibrium bond lengths, harmonic and anharmonic vibrational constants, fundamental frequencies, and dissociation energies, are in good agreement with those of time-dependent four-component relativistic density-functional theory and ab initio multireference second-order perturbation theory. Nonetheless, this two-component relativistic version of time-dependent density-functional theory is only moderately advantageous over the four-component one as far as computational efforts are concerned.