Real-space pseudopotential method for first principles calculations of general periodic and partially periodic systems

Natan, Amir; Benjamini, Ayelet; Naveh, Doron; Kronik, Leeor; Tiago, Murilo L.; Beckman, Scott P.; Chelikowsky, James R.

doi:10.1103/physrevb.78.075109

Cited by 88 publications

(90 citation statements)

References 60 publications

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“…12 This sparseness leads to good parallelizability in the diagonalization of the KS matrix, because communication is only required when off-diagonal blocks connect grid elements on different processors. 13,[15][16][17] Unfortunately, these advantages do not carry over to direct inversion because the inverse of a sparse matrix is generally non-sparse.…”

Section: Complex Energy Diagonalizationmentioning

confidence: 99%

Real-space method for highly parallelizable electronic transport calculations

et al. 2014

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We present a real-space method for first-principles nano-scale electronic transport calculations. We use the non-equilibrium Green's function method with density functional theory and implement absorbing boundary conditions (ABCs, also known as complex absorbing potentials, or CAPs) to represent the effects of the semi-infinite leads. In real space, the Kohn-Sham Hamiltonian matrix is highly sparse. As a result, the transport problem parallelizes naturally and can scale favorably with system size, enabling the computation of conductance in relatively large molecular junction models. Our use of ABCs circumvents the demanding task of explicitly calculating the leads' self-energies from surface Green's functions, and is expected to be more accurate than the use of the jellium approximation. In addition, we take advantage of the sparsity in real space to solve efficiently for the Green's function over the entire energy range relevant to low-bias transport. We illustrate the advantages of our method with calculations on several challenging test systems and find good agreement with reference calculation results.

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Section: Complex Energy Diagonalizationmentioning

confidence: 99%

Real-space method for highly parallelizable electronic transport calculations

et al. 2014

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“…In our implementation we used the exact cutoff method described in Ref. 46 along the non-periodic dimension and employed non-orthogonal grids 47 , optimized according to the lattice symmetries, on the periodic ones. Our implementation is fully parallel in grid points, k-points, bands and spin dimension.…”

Section: Applications a Computational Detailsmentioning

confidence: 99%

A First-Principles Time-Dependent Density Functional Theory Framework for Spin and Time-Resolved Angular-Resolved Photoelectron Spectroscopy in Periodic Systems

Giovannini

Hübener

Rubio

2016

J. Chem. Theory Comput.

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We present a novel theoretical approach to simulate spin, time and angular-resolved photoelectron spectroscopy (ARPES) from first principles that is applicable to surfaces, thin films, few layer systems, and low-dimensional nanostructures. The method is based on a general formulation in the framework of time-dependent density functional theory (TDDFT) to describe the real timeevolution of electrons escaping from a surface under the effect of any external (arbitrary) laser field. By extending the so called t-SURFF method to periodic systems one can calculate the final photoelectron spectrum by collecting the flux of the ionization current trough an analysing surface. The resulting approach, that we named t-SURFFP, allows to describe a wide range of irradiation conditions without any assumption on the dynamics of the ionization process allowing for pumpprobe simulations on an equal footing. To illustrate the wide scope of applicability of the method we present applications to graphene, mono-and bi-layer WSe2, and hexagonal BN under different laser configurations.

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“…Our calculations were performed using parsec, [26][27][28] a real-space implementation of pseudopotentials within density functional theory. 29,30 parsec solves the KohnSham equations self-consistently on an orthogonal, uniform, three-dimensional grid on real-space.…”

Section: Methodsmentioning

confidence: 99%

Structural evolution of the Pb/Si(111) interface with metal overlayer thickness

et al. 2015

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We a employ real-space pseudopotential method to compute the structural energies of a prototypical system metal-semiconductor interface. Specifically, we examine a Pb(111) film overlaid on a Si(111) substrate as a function of the metal thickness. For each layer of Pb we fully relax the atomic coordinates and determine the lowest energy structure. Owing to the lattice mismatch between the Pb and Si crystal structures, we consider a large supercell containing up to 1,505 atoms for the largest system. Systems of this size remain challenging for most current computational approaches and require algorithms specifically designed for highly parallel computational platforms. We examine the structural properties of the interface with respect to the thickness of the metal overlayer, e.g., the corrugation of the profile of the Pb overlayer. The combined influence of the Si substrate and quantum confinement results in a rich profile for a transition between a thin overlayer (less than a few monolayers) where the corrugation is strong, and the bulk region, (more than a half dozen layers) where the overlaid Pb film is atomically flat. This work proves the feasibility of handling systems with such a level of complexity.

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Real-space pseudopotential method for first principles calculations of general periodic and partially periodic systems

Cited by 88 publications

References 60 publications

Real-space method for highly parallelizable electronic transport calculations

Real-space method for highly parallelizable electronic transport calculations

A First-Principles Time-Dependent Density Functional Theory Framework for Spin and Time-Resolved Angular-Resolved Photoelectron Spectroscopy in Periodic Systems

Structural evolution of the Pb/Si(111) interface with metal overlayer thickness

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