Kauczor Joanna, Norman Patrick
Department of Physics, Chemistry and Biology, Linköping University , SE-581 83 Linköping, Sweden.
J Chem Theory Comput. 2014 Jun 10;10(6):2449-55. doi: 10.1021/ct500114m.
Molecular spectra can be determined from molecular response functions, by solving the so-called damped response equations using the complex polarization propagator approach. The overall structure of response equations is identical for variational wave functions such as the Hartree-Fock, multiconfiguration self-consistent field, and Kohn-Sham density functional theory, and the key program module is the linear response equation solver. We present an implementation of the solver using the algorithm with symmetrized vectors, optimized for addressing spectral regions of a width of some 5-10 eV and a resolution below 0.1 eV. The work is illustrated by the consideration of UV-vis as well as near carbon K -edge absorption spectra of the C60 fullerene. We demonstrate that it is possible to converge tightly response equations for hundreds of optical frequencies in resonance regions of the spectrum at a cost not much exceeding the solution of a single response equation in the nonresonant region. Our work is implemented in the molecular orbital based module of the Dalton program and serves as a documentation of the code distributed in the Dalton2013 release version.
分子光谱可通过分子响应函数来确定，即使用复极化传播子方法求解所谓的阻尼响应方程。对于诸如哈特里 - 福克、多组态自洽场和科恩 - 沙姆密度泛函理论等变分波函数，响应方程的整体结构是相同的，关键程序模块是线性响应方程求解器。我们展示了一种使用对称化向量算法的求解器实现方式，该算法针对宽度约为5 - 10 eV且分辨率低于0.1 eV的光谱区域进行了优化。通过考虑C60富勒烯的紫外 - 可见光谱以及近碳K边吸收光谱来说明这项工作。我们证明，在光谱的共振区域中，对于数百个光学频率的响应方程能够紧密收敛，其成本并不比非共振区域单个响应方程的求解成本高太多。我们的工作在道尔顿程序基于分子轨道的模块中实现，并作为Dalton2013发行版中分发代码的文档。
