Density functional theory treatment of electron correlation in the nuclear-electronic orbital approach.
Density functional theory treatment of electron correlation in the nuclear-electronic orbital approach.
复制标题
核电子轨道方法中电子关联的密度泛函理论处理。
DOI：
10.1021/jp0704463
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
S. Hammes‐Schiffer
中科院分区：
文献类型：
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作者：
M. V. Pak;A. Chakraborty;S. Hammes‐Schiffer
本文提出了核电子轨道密度泛函理论[NEO-DFT(ee)]方法，将电子-电子相关性和核量子效应自洽地纳入量子化学计算中。 NEO 方法旨在以量子力学方式处理相对少量的原子核，而其余的原子核则采用经典处理方式。在 NEO-DFT(ee) 方法中，相关电子密度用于获取核分子轨道，而所得核密度用于在迭代过程中获取相关电子密度，该迭代过程持续到核密度和电子密度收敛。该方法包括相关电子密度和核波函数之间的反馈。将此方法应用于二卤化物和乙炔表明，核量子效应不会显着影响电子相关能，但量子核能在 NEO-DFT(ee) B3LYP 方法中得到增强。 NEO-DFT(ee) 优化的双卤化物结构与基于网格的量子动力学方法的振动平均几何结构的出色一致性为 NEO-DFT(ee) 方法提供了验证。电子-质子相关性可以通过电子-核相关函数的开发来包含。或者，可以将显式的电子-质子相关性直接包含到具有高斯型孪生函数的 NEO 自洽场框架中。
This paper presents the nuclear-electronic orbital density functional theory [NEO-DFT(ee)] method for including electron-electron correlation and nuclear quantum effects self-consistently in quantum chemical calculations. The NEO approach is designed to treat a relatively small number of nuclei quantum mechanically, while the remaining nuclei are treated classically. In the NEO-DFT(ee) approach, the correlated electron density is used to obtain the nuclear molecular orbitals, and the resulting nuclear density is used to obtain the correlated electron density during an iterative procedure that continues until convergence of both the nuclear and electronic densities. This approach includes feedback between the correlated electron density and the nuclear wavefunction. The application of this approach to bihalides and acetylene indicates that the nuclear quantum effects do not significantly impact the electron correlation energy, but the quantum nuclear energy is enhanced in the NEO-DFT(ee) B3LYP method. The excellent agreement of the NEO-DFT(ee)-optimized bihalide structures with the vibrationally averaged geometries from grid-based quantum dynamical methods provides validation for the NEO-DFT(ee) approach. Electron-proton correlation could be included by the development of an electron-nucleus correlation functional. Alternatively, explicit electron-proton correlation could be included directly into the NEO self-consistent-field framework with Gaussian-type geminal functions.