Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165-TC, A-1060 Vienna, Austria.
J Chem Phys. 2018 Oct 14;149(14):144105. doi: 10.1063/1.5048907.
A recent study of Mejia-Rodriguez and Trickey [Phys. Rev. A , 052512 (2017)] showed that the deorbitalization procedure (replacing the exact Kohn-Sham kinetic-energy density by an approximate orbital-free expression) applied to exchange-correlation functionals of the meta-generalized gradient approximation (MGGA) can lead to important changes in the results for molecular properties. For the present work, the deorbitalization of MGGA functionals is further investigated by considering various properties of solids. It is shown that depending on the MGGA, common orbital-free approximations to the kinetic-energy density can be sufficiently accurate for the lattice constant, bulk modulus, and cohesive energy. For the bandgap, calculated with the modified Becke-Johnson MGGA potential, the deorbitalization has a larger impact on the results.
梅希亚-罗德里格斯和特里克[Phys. Rev. A, 052512 (2017)]的最近一项研究表明，对于交换关联泛函的脱轨道处理（用近似无轨道的表达式替换精确的 Kohn-Sham 动能密度）应用于泛函的meta 广义梯度近似（meta-GGA）可以导致分子性质结果的重要变化。对于目前的工作，通过考虑固体的各种性质，进一步研究了 GGA 泛函的脱轨道处理。结果表明，取决于 GGA，常见的无轨道动能密度近似对于晶格常数、体弹性模量和内聚能可以足够准确。对于带隙，用修正的贝克-约翰逊 GGA 势计算，脱轨道处理对结果的影响更大。
