A new, very fast, implementation of the exact (Fock) exchange operator for electronic structure calculations within the plane-wave pseudopotential method is described in detail for both molecular and periodic systems, and carefully validated. Our method combines the recently proposed Adaptively Compressed Exchange approach, to reduce the number of times the exchange is evaluated in the self-consistent loop, with an orbital localization procedure that reduces the number of exchange integrals to be computed at each evaluation and potentially the compute time of each of them. The new implementation, already available in the Quantum ESPRESSO distribution, results in a speedup that is never smaller than 3-4x and that increases with the size of the system, according to various realistic benchmark calculations.
Faster Exact Exchange for Solids via occ-RI-K: Application to Combinatorially Optimized Range-Separated Hybrid Functionals for Simple Solids with Pseudopotentials Near the Basis Set Limit
In this work, we developed and showcased the occ-RI-K algorithm to compute the exact exchange contribution in density functional calculations of solids near the basis set limit. Within the gaussian planewave (GPW) density fitting, our algorithm achieves a 1-2 orders of magnitude speedup compared to conventional GPW algorithms. Since our algorithm is well-suited for simulations with large basis sets, we applied it to 12 hybrid density functionals with pseudopotentials and a large uncontracted basis set to assess their performance on band gaps of 25 simple solids near the basis set limit. The la…
Hybrid-functional calculations with plane-wave basis sets: The effect of the singularity correction on total energies, energy eigenvalues, and defect energy levels
Hybrid preconditioning for iterative diagonalization of ill-conditioned generalized eigenvalue problems in electronic structure calculations
一系列大型病态广义本征值问题的迭代对角化是量子力学{ \em ab initio}电子结构计算中采用非正交基的计算瓶颈。我们提出了一个混合预处理方案，有效地结合全球和本地加速预处理器的快速迭代对角化等特征值问题。在单位分割有限元（PUFE）赝势密度泛函计算中，采用非正交基，我们证明了混合预处理块最速下降法是一种具有成本效益的本征解，优于当前最先进的全局预处理方案，对于由PUFE产生的病态广义特征值问题，作为局部最优块预条件共轭，梯度法求解由平面波方法产生的条件良好的标准特征值问题。
Fast and Scalable GPU-Accelerated Quantum Chemistry for Periodic Systems with Gaussian Orbitals: Implementation and Hybrid Density Functional Theory Calculations
From anti-perovskite to double anti-perovskite: lattice chemistry basis for super-fast transportation of Li+ ions in cubic solid lithium halogen-chalcogenides
