TY  - RPRT
TI  - Active-space coupled-cluster methods through connected quadruple excitations.
AU  - Peng-Dong Fan
AU  - So Hirata
PY  - 2006
DO  - 10.1063/1.2178797
UR  - https://pubmed.ncbi.nlm.nih.gov/16542069/
ID  - 16542069
ER  -