标题： 多电子问题的自然轨道泛函 显示英文标题

标题： A natural orbital functional for the many-electron problem

摘要： 在Kohn-Sham密度泛函理论中，交换相关能量表示为电子密度和Kohn-Sham轨道的泛函。 Kohn-Sham理论的一种替代方法是将能量表示为约化一阶密度矩阵或等效自然轨道的泛函。 在前一种方法中，泛函的未知部分同时包含动能和势能贡献，而在后一种方法中，它仅包含势能，因此具有更简单的标度性质。 我们提出了一种基于纯标度论证和近似满足求和规则的自然轨道的近似、简单且无参数的泛函。 我们在原子上的测试表明，与哈特里-福克方法、局域密度近似和广义梯度近似相比，它平均能提供更准确的能量和电荷密度。 显示英文摘要

摘要： The exchange-correlation energy in Kohn-Sham density functional theory is expressed as a functional of the electronic density and the Kohn-Sham orbitals. An alternative to Kohn-Sham theory is to express the energy as a functional of the reduced first-order density matrix or equivalently the natural orbitals. In the former approach the unknown part of the functional contains both a kinetic and a potential contribution whereas in the latter approach it contains only a potential energy and consequently has simpler scaling properties. We present an approximate, simple and parameter-free functional of the natural orbitals, based solely on scaling arguments and the near satisfaction of a sum rule. Our tests on atoms show that it yields on average more accurate energies and charge densities than the Hartree Fock method, the local density approximation and the generalized gradient approximations.