Calculation of first-order one-electron properties using the coupled-cluster approximate triples model CC3

Abstract

The calculation of first-order one-electron molecular properties is discussed for the iterative approximate coupled-cluster triples model CC3. The implementation which has the computational scaling N⁷ uses an explicitly spin coupled excitation space. Sample calculations are presented for the quadrupole moments of ethylene where the largest calculation uses an aug-cc-pVQZ basis which contains 344 basis functions.