首先说一个事实：在最初的 DFT 理论中，是没有 orbital 的概念的。也即 DFT 本来就应该是一套 orbital-free 的理论。Hohenberg-Kohn 第一定理（HK-I）说：体系的电子能量只是电子密度的泛函，也即：E≡E[ρ]，不依赖于其他变量。这个结果是令人震惊的，因为如果按照传统的量子力学的表述，能量是哈密顿量在波...
我从电子结构的角度补充一下这背后的 motivation,也即为什么人们想发展 orbital-free 的 DFT,为什么这样做是合理的 etc. 首先说一个事实:在最初的 DFT 理论中,是没有 orbital 的概念的。也即 DFT 本来就应该是一套 orbital-free 的理论。Hohenberg-Kohn 第一定理(HK-I)说:体系的电子能量只是电子密度的泛函,...
Electronic structure calculations at macroscopic scales using orbital-free DFTIn this chapter we provide an overview of the recently developed coarse-graining technique for orbital-free density functional theory that enables electronic structure calculations on multi-million atoms. The key ideas involved ...
Ec is the DFT correlation energy. It often is useful to write Exc = Ex + Ec. Vˆee is the electron–electron Coulomb interaction. The KS Slater determinant Φs[n] is comprised of orbitals from the KS system Euler equations, ɛhKS[n]φi=ɛiφi,n(r)=∑ifi|φi(r)|2. Here ...
Orbital-free density functional theory (OFDFT) is a quantum chemistry formulation that has a lower cost scaling than the prevailing Kohn–Sham DFT, which is increasingly desired for contemporary molecular research. However, its accuracy is limited by the kinetic energy density functional, which is ...
Orbital-free density functional theory (OF-DFT) is an electronic structure method with a low computational cost that scales linearly with the number of simulated atoms, making it suitable for large-scale material simulations. It is generally considered that OF-DFT strictly requires the use of local...
Orbital-free DFT has been observed to work well for systems with weakly varying electron density, most promine...Ligneres, V. L.; Carter, E. A. An Introduction to Orbital-Free Density Functional Theory. In Handbook of Materials Modeling; Yip, S. Ed.; Springer: Netherlands, 2005; pp ...
Orbital-free density functional theory (OF-DFT) is a promising method for large-scale quantum mechanics simulation as it provides a good balance of accuracy and computational cost. Its applicability to large-scale simulations has been aided by progress in constructing kinetic energy functionals and lo...
似乎可以算Thomas-Fermi层次的，但是不知道怎么用。谁能发给我一个例子？help ...
We present a quantum mechanics (QM)/molecular mechanics (MM) formalism for coupling density functional theory (DFT) based quantum simulations to classical atomistic simulations for metals. The multiscale methodology is applicable to systems where important quantum phenomena are confined to a small region...