Optimizing the FEDVR-TDCC Code for Exploring the Quantum Dynamics of Two-Electron Systems in Intense Laser Pulses

Journal Article · Wed May 19 00:00:00 EDT 2010 · Physical Review E

DOI:https://doi.org/10.1103/PhysRevE.81.056705· OSTI ID:979404

Hu, S X

To efficiently solve the three-dimensional (3D) time-dependent linear and nonlinear Schrödinger equation, we have developed a large-scale parallel code RSP-FEDVR [B. I. Schneider, L. A. Collins, and S. X. Hu, Phys. Rev. E 73, 036708 (2006)], which combines the finite-element discrete variable representation (FEDVR) with the real-space product algorithm. Using the similar algorithm, we have derived an accurate approach to solve the time-dependent close-coupling (TDCC) equation for exploring two-electron dynamics in linearly polarized intense laser pulses. However, when the number N of partial waves used for the TDCC expansion increases, the FEDVR-TDCC code unfortunately slows down, because the potential-matrix operation scales as ~O(N^2). In this paper, we show that the full potential-matrix operation can be decomposed into a series of small-matrix operations utilizing the sparse property of the N N potential matrix. Such optimization speeds up the FEDVR-TDCC code by an order of magnitude for N=256. This may facilitate the ultimate solution to the 3D two-electron quantum dynamics in ultrashort intense optical laser pulses, where a large number of partial waves are required.

• Research Organization: Univ. of Rochester, NY (United States). Lab. for Laser Energetics
• Sponsoring Organization: USDOE
• DOE Contract Number: FC52-08NA28302
• OSTI ID: 979404
• Report Number(s): DOE/NA/28302-952; ISSN 1550-2376; 2010-65; 1935
• Journal Information: Physical Review E, Vol. 81, Issue 5; ISSN 1539-3755
• Country of Publication: United States
• Language: English