3D finite difference modeling via domain decomposition

1996 ◽  
Author(s):  
Alberto Villarreal ◽  
John A. Scales
Keyword(s):  
Finite Difference ◽  
Domain Decomposition

Fast Domain Decomposition Type Solver for Stiffness Matrices of Reference p-Elements

2013 ◽  
Vol 13 (2) ◽  
pp. 161-183 ◽  
Author(s):  
Vadim Korneev
Keyword(s):  
Finite Difference ◽  
Domain Decomposition ◽  
Elliptic Equations ◽  
Harmonic Functions ◽  
Schur Complement ◽  
P Elements ◽  
Stiffness Matrices ◽  
The Family ◽  
Discrete Harmonic Functions

Abstract. A key component of domain decomposition solvers for hp discretizations of elliptic equations is the solver for internal stiffness matrices of p-elements. We consider an algorithm which belongs to the family of secondary domain decomposition solvers, based on the finite-difference like preconditioning of p-elements, and was outlined by the author earlier. We remove the uncertainty in the choice of the coarse (decomposition) grid solver and suggest the new interface Schur complement preconditioner. The latter essentially uses the boundary norm for discrete harmonic functions induced by orthotropic discretizations on slim rectangles, which was derived recently. We prove that the algorithm has linear arithmetical complexity.

Numerical Methods for Solving the Hartree-Fock Equations of Diatomic Molecules II

2016 ◽  
Vol 19 (3) ◽  
pp. 632-647 ◽  
Author(s):  
John C. Morrison ◽  
Kyle Steffen ◽  
Blake Pantoja ◽  
Asha Nagaiya ◽  
Jacek Kobus ◽  
...  
Keyword(s):  
Partial Differential Equations ◽  
Finite Difference ◽  
Differential Equations ◽  
Domain Decomposition ◽  
Diatomic Molecule ◽  
Linear Equations ◽  
Finite Difference Approximation ◽  
Partial Differential ◽  
Hartree Fock ◽  
Finite Difference Approach

AbstractIn order to solve the partial differential equations that arise in the Hartree- Fock theory for diatomicmolecules and inmolecular theories that include electron correlation, one needs efficient methods for solving partial differential equations. In this article, we present numerical results for a two-variablemodel problem of the kind that arises when one solves the Hartree-Fock equations for a diatomic molecule. We compare results obtained using the spline collocation and domain decomposition methods with third-order Hermite splines to results obtained using the more-established finite difference approximation and the successive over-relaxation method. The theory of domain decomposition presented earlier is extended to treat regions that are divided into an arbitrary number of subregions by families of lines parallel to the two coordinate axes. While the domain decomposition method and the finite difference approach both yield results at the micro-Hartree level, the finite difference approach with a 9- point difference formula produces the same level of accuracy with fewer points. The domain decompositionmethod has the strength that it can be applied to problemswith a large number of grid points. The time required to solve a partial differential equation for a fine grid with a large number of points goes down as the number of partitions increases. The reason for this is that the length of time necessary for solving a set of linear equations in each subregion is very much dependent upon the number of equations. Even though a finer partition of the region has more subregions, the time for solving the set of linear equations in each subregion is very much smaller. This feature of the theory may well prove to be a decisive factor for solving the two-electron pair equation, which – for a diatomic molecule – involves solving partial differential equations with five independent variables. The domain decomposition theory also makes it possible to study complex molecules by dividing them into smaller fragments that are calculated independently. Since the domain decomposition approachmakes it possible to decompose the variable space into separate regions in which the equations are solved independently, this approach is well-suited to parallel computing.

Sign in / Sign up

Export Citation Format

Share Document