Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Last revisionBoth sides next revision
the_closed_shell_ccsd_program [2023/01/30 22:45] – [Coupled-cluster, CCSD] hesselmannthe_closed_shell_ccsd_program [2023/01/30 22:53] – [Coupled-cluster, CCSD] hesselmann
Line 49: Line 49:
  
  
-CCSD calculations with KS orbitals are possible. Optionally, the ''H0'' option can be used to specify the zeroth-order Hamiltonian (see options above). If KS or other non-HF reference states (like the Brueckner determinant) are employed in the calculation of the triples (T) additional singles terms are computed. This can be switched on/off with the option ''TRIP_FIA=1/0''. If ''TRIP_FIA=1'' the second order singles energy is computed in the triples program and if greater in magnitude than ''THR_E2SING'' the additional terms will be computed. +CCSD calculations with KS orbitals are possible. Optionally, the ''H0'' option can be used to specify the zeroth-order Hamiltonian (see options above). If KS or other non-HF reference states (like the Brueckner determinant) are employed in the calculation of the triples (T) additional singles terms are computed, see J. D. Watts, J. Gauss, R. Bartlett [[https://doi.org/10.1063/1.464480|J. Chem. Phys.]] **98**, 8718 (1993). This can be switched on/off with the option ''TRIP_FIA=1/0''. If ''TRIP_FIA=1'' the second order singles energy is computed in the triples program and if greater in magnitude than ''THR_E2SING'' the additional terms will be computed. 
-''THR_E2SING=1d-6'' is the default setting for this threshold, which can also be altered via an option to the CCSD program.+''THR_E2SING=1d-6'' is the default setting for this threshold, which can also be altered via giving this keyword as an option to the CCSD program.