## Simulation Science Lab: Computational Materials ScienceGerman Research School for Simulation Sciences and RWTH Aachen UniversityWS 2013/14, Fr 09:45-12:00, Lecture Hall, GRS Jülich note change in place and time!CAMPUS link ## Lectures**Introduction** preparation:- clone
`SiScLab13`to your laptop and RWTH cluster account - read Sec. 1 and 2.1 on the Lanczos method
- if you need a refresher on second quantization, read Sec. 1, 2, and 4 on many-body states
tight-binding approximation many-electron states Hubbard model
- clone
**Many-body hopping** setting up lookup tables for basis states counting the number of set bits operations on the many-body states: bit-operations hopping Hamiltonian on the many-body Hilbert space sparse matrix representation
**Many-body states** disassembling your code and checking intrinsics sparse representation of many-body hopping Slater determinants representation of many-body states
**Lanczos iteration** allocating large vectors basic linear algebra operations compiler optimizations Lanczos iteration
**Debugging** example codes:`basic.c`and`test.c`
**Cache** interpreting profiles: number of calls, timing/scaling Lieb-Wu solution for the infinite Hubbard-chain cache optimization**Cache in Practice:** cachegrind
**Trading memory access for computation** Hubbard interaction without lookup tables
Erik Koch |