Quasienergy formulation of damped response theory.
Quasienergy formulation of damped response theory.
复制标题
阻尼响应理论的准能量公式。
DOI：
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发表时间：
2009
影响因子：
4.4
通讯作者：
P. Jørgensen
中科院分区：
文献类型：
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作者：
K. Kristensen;J. Kauczor;T. Kjaergaard;P. Jørgensen
我们提出了一个准能量为基础的制定阻尼响应理论，一个共同的有效寿命参数已被引入到所有的激发态的复杂的激发能。有限激发态寿命的引入导致一组（复杂的）阻尼响应方程，它具有相同的形式的所有订单的扰动。给出了Hartree-Fock理论和Kohn-Sham密度泛函理论中阻尼响应方程的一种求解算法。准能量公式的使用使我们能够通过应用一组响应参数消除规则直接获得阻尼响应函数的计算上最简单的表达式，该规则最小化要求解的阻尼响应方程的总数。在标准响应理论中，加宽的吸收光谱是通过在吸收棒光谱上叠加特殊的线形函数而获得的，而所有激发共同的经验线形函数是阻尼响应理论的一个组成部分。通过将阻尼响应理论中固有的线形函数叠加到标准响应理论的棒谱上，我们证明了标准响应理论和阻尼响应理论计算得到的吸收谱是相同的。我们表明，阻尼响应理论可以应用于获得在所有频率范围内的吸收光谱，也是那些不容易解决使用标准响应理论。这使得阻尼响应理论成为一种有效的工具，例如，用于确定大分子的吸收光谱，其中激发态的密度可能非常高，并且其中标准响应理论因此在实践中不适用。给出了我们的阻尼响应理论公式与Norman等人[J. Chem. Phys. 123，194 - 103（2005）]的公式之间的全面比较。
We present a quasienergy-based formulation of damped response theory where a common effective lifetime parameter has been introduced for all excited states in terms of complex excitation energies. The introduction of finite excited state lifetimes leads to a set of (complex) damped response equations, which have the same form to all orders in the perturbation. An algorithm is presented for solving the damped response equations in Hartree-Fock theory and Kohn-Sham density functional theory. The use of the quasienergy formulation allows us to obtain directly the computationally simplest expressions for damped response functions by applying a set of response parameter elimination rules, which minimize the total number of damped response equations to be solved. In standard response theory broadened absorption spectra are obtained by ad hoc superimposing lineshape functions onto the absorption stick spectra, whereas an empirical lineshape function common to all excitations is an integrated part of damped response theory. By superimposing the lineshape functions inherent in damped response theory onto the stick spectra of standard response theory, we show that the absorption spectra obtained in standard and damped response theory calculations are identical. We demonstrate that damped response theory may be applied to obtain absorption spectra in all frequency ranges, also those that are not readily addressed using standard response theory. This makes damped response theory an effective tool, e.g., for determining absorption spectra for large molecules, where the density of the excited states may be very high, and where standard response theory therefore is not applicable in practice. A thorough comparison is given between our formulation of damped response theory and the formulation by Norman et al. [J. Chem. Phys. 123, 194103 (2005)].