A graphical symmetric group approach for a spin adapted full configuration interaction: partitioning of a configuration graph into sets of closed-shell and open-shell graphs

摘要: We developed a spin adapted full configuration interaction (FCI) method which was expected to be effective for parallel processing. The graphical symmetric group approach (GSGA) employed, where graph partitioned into several sets of closed-shell and open-shell graphs. state functions (CSFs) bearing the same number closed-shells open-shells were assembled in group. provided identify each CSF sequential order within Combination this partitioning an intermediate configuration-driven algorithm calculating so-called σ vectors allowed us use symbolic coupling constants. Furthermore, combination made it easy implement efficient suitable task-distributed procedure evaluating vectors. A program written some test calculations carried out with high efficiency. largest size FCI used 10 million CSFs (20 determinants).