Large-scale parallel configuration interaction. I. Nonrelativistic and scalar-relativistic general active space implementation with application to (Rb-Ba)+.

摘要: We present a parallel implementation of string-driven general active space configuration interaction program for nonrelativistic and scalar-relativistic electronic-structure calculations. The code has been modularly incorporated in the DIRAC quantum chemistry package. is based on message passing interface distributed data model order to efficiently exploit key features various modern computer architectures. exemplify nearly linear scalability our large-scale multireference (MRCI) calculations, we discuss speedup with respect machine-dependent aspects. largest sample MRCI calculation includes 1.5×109 Slater determinants. Using new determine first time full short-range electronic potentials spectroscopic constants ground state eight low-lying excited states weakly bound molecular system (Rb–Ba)+ spin-orbit-free Dirac formalism using extensive uncontracted basis sets. required compute convergence these single-point correlating 18 electrons 16 cores was reduced from more than 10days less 1day.