Seminar: Victor P. Vysotskiy

University of Heidelberg

P-RICDΣ: A highly scalable parallel platform for calculating ionization potentials and electron affinities in large quantum systems via Green’s Function method

Monday, June 27, 2:00 p.m.
307 Eberly Hall

 

Overview: To treat the electronic structure in large quantum systems via state-of-the-art second-order electron propagator method (ADC(2)) we developed a highly scalable parallel computer program called P−RICDΣ [1]. The parallel efficiency has been achieved by utilizing the hybrid MPI/OpenMP programming model and exploiting the sparsity of the two-electron integral matrix by using Cholesky decomposition techniques. By using the P−RICDΣ program and a massively parallel computer we are now able to tackle grand challenge-class problems (in the size-range of a few hundredths of atoms and thousands of basis functions) which were unattainable before within the framework of conventional techniques.

The talk is organized as follows:

  1. Brief introduction to the basics of the Cholesky decomposition technique and its various modifications;
  2. Introduction to the second-order Green’s function method; working equations;
  3. Technical aspects of the efficient MPI/OpenMP parallelization of working equations
  4. Timings and scaling behavior of the P−RICDΣ program
  5. Future prospect and perspectives: utilizing a specialized floating-point mathematical coprocessors (GPGPU) in single precision mode [2].

References:

  1. Victor P. Vysotskiy and Lorenz S. Cederbaum, Journal of Chemical Physics 132, 044110 (2010)
  2. Victor P. Vysotskiy and Lorenz S. Cederbaum, Journal of Chemical Theory and Computation 7, 320 (2011)

Sponsored by: Center for Molecular and Materials Simulations at the University of
Pittsburgh.