Hyperpolarizabilities of closed-shell atoms and ions in the local-density approximation.
Hyperpolarizabilities of closed-shell atoms and ions in the local-density approximation.
复制标题
局域密度近似中闭壳原子和离子的超极化率。
DOI：
10.1103/physreva.34.3619
复制
发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Subbaswamy
中科院分区：
文献类型：
--
作者：
Senatore;Subbaswamy
将密度泛函理论的局域密度近似（LDA）应用于稀有气体原子的静态超极化率的计算。发现简单LDA预测立方超极化率。伽马..大了大约2倍。有人认为，LDA预测的原子中的电子云的过度变形性是这种近似处理的电子分布的尾部的方式的一个工件。LDA在原子尾区性能不佳的原因之一是由于在这样的方案中存在电子与自身的相互作用。因此，考虑了LDA的修改，其中减去自相互作用。当应用到他，该方法产生的线性和立方偶极极化率与实验合理的协议。改进的方案也适用于较重的稀有气体和一些负离子（H/sup -/，F/sup -/，Cl/sup -/）。通过将自相互作用修正限制在未微扰原子问题上，克服了处理具有两个以上电子的原子（离子）时遇到的困难。一个系统的减少之间的差异计算的静态超极化率和那些从最近的有限频率测量推断ismore »发现。«少
The local-density approximation (LDA) of density-functional theory is applied to the computation of static hyperpolarizabilities of rare-gas atoms. It is found that simple LDA predicts cubic hyperpolarizabilities ..gamma.. that are too large by approximately a factor of 2. It is argued that the excessive deformability of the electronic clouds in atoms predicted by LDA is an artifact of the way this approximation treats the tail of the electronic distribution. One of the causes for the poor performance of LDA in the tail region of an atom is ascribed to the presence in such a scheme of interactions of the electrons with themselves. Therefore, a modification of the LDA is considered in which self-interactions are subtracted. When applied to He, the method yields both linear and cubic dipole polarizabilities in reasonable agreement with experiments. The modified scheme is also applied to heavier rare gases and to some negative ions (H/sup -/, F/sup -/, Cl/sup -/). Difficulties that are encountered in dealing with atoms (ions) with more than two electrons are overcome by limiting the self-interaction corrections to the unperturbed atom problem. A systematic reduction of the discrepancies between the calculated static hyperpolarizabilities and those inferred from recent finite frequency measurements ismore » found.« less