There are a large number of options for the coupled-cluster singles and doubles methods. They are documented in Appendix C, and, as the reader will find upon following this link, it is an extensive list indeed. Fortunately, many of them are not necessary for routine jobs. Most of the options for non-routine jobs concern altering the default iterative procedure, which is most often necessary for optimized orbital calculations (OD, QCCD), as well as the active space and EOM methods discussed later in Section 6.10. The more common options relating to convergence control are discussed there, in Section 6.10.6. Below we list the options that one should be aware of for routine calculations.
For memory options and parallel execution, see Section 6.14.
Note: For single point calculations, CC_E_CONV = 6 and CC_T_CONV = 4. Tighter amplitude convergence (CC_T_CONV = 5) is used for gradients and EOM calculations.