Some strategies for enhancing the performance of the block Lanczos method

Conference · Fri Jan 01 00:00:00 EST 1988

DOI:https://doi.org/10.1016/0010-4655(89)90151-3· OSTI ID:6904966

Kress, J D; Woodruff, S B; Parker, G A; Pack, R T

The block Lanczos method is used to calculate the eigenfunctions for a generalized eigenvalue problem constructed for a finite element solution to a 2-dimensional Schr/umlt o/dinger equation on the surface of a hypersphere. This equation results from a treatment of the 3-dimensional reactive scattering problem using Adiabatically adjusting. Principal axes Hyperspherical (APH) coordinates. Three stategies are considered with respect to increasing the CPU performance of the block Lanczos (with selective orthogonalization) method: (1) the effect of varying the Lanczos block size: (2) the effect of solving the block tridiagonal ordinary eigenvalue problem upon every other Lanczos iteration; and, (3) the effect of dividing a single problem of finding p eigenvalues into a set of p/sub i/ problems, where each subproblem consists of finding p/p/sub i/ eigenvalues.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6904966
• Report Number(s): LA-UR-88-2482; CONF-8810119-2; ON: DE88014401
• Resource Relation: Journal Volume: 53; Journal Issue: 1-3; Conference: Workshop on practical iterative methods for large scale computations, Minneapolis, MN, USA, 23 Oct 1988; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EIGENFUNCTIONS
COMPUTER CALCULATIONS
SCHROEDINGER EQUATION
PERFORMANCE
SCATTERING
DIFFERENTIAL EQUATIONS
EQUATIONS
FUNCTIONS
PARTIAL DIFFERENTIAL EQUATIONS
WAVE EQUATIONS
657002* - Theoretical & Mathematical Physics- Classical & Quantum Mechanics