Some strategies for enhancing the performance of the block Lanczos method

Conference · Fri Jan 01 04:00:00 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 Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6904966
• Report Number(s): LA-UR-88-2482; CONF-8810119-2; ON: DE88014401
• Country of Publication: United States
• Language: English

Related Subjects

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