6533b829fe1ef96bd128a5af
RESEARCH PRODUCT
Equation-of-motion coupled-cluster methods for ionized states with an approximate treatment of triple excitations.
Jamal C. SaehMihály KállayPéter G. SzalayYannick J. BombleJürgen GaussJohn F. Stantonsubject
Bond lengthCoupled clusterChemistryIonizationHarmonicGeneral Physics and AstronomyEquations of motionPhysics::Chemical PhysicsPhysical and Theoretical ChemistryAtomic physicsIonization energyFull configuration interactionDiatomic moleculedescription
The accuracy of geometries and harmonic vibrational frequencies is evaluated for two equation-of-motion ionization potential coupled-cluster methods including CC3 and CCSDT-3 triples corrections. The first two Sigma states and first Pi state of the N2 +, CO+, CN, and BO diatomic radicals are studied. The calculations show a tendency for the CC3 variant to overestimate the bond lengths and to underestimate the vibrational frequencies, while the CCSDT-3 variant seems to be more reliable. It is also demonstrated that the accuracy of such methods is comparable to sophisticated traditional multireference approaches and the full configuration interaction method.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2005-04-15 | The Journal of chemical physics |