6533b826fe1ef96bd1283f3d
RESEARCH PRODUCT
Analytic evaluation of the dipole Hessian matrix in coupled-cluster theory
Kenneth RuudThomas-c. JagauJürgen Gausssubject
Hessian matrixChemistryAnharmonicityGeneral Physics and AstronomyVDP::Mathematics and natural science: 400::Chemistry: 440::Theoretical chemistry quantum chemistry: 444Third derivativeMoment (mathematics)symbols.namesakeDipoleCoupled clusterClassical mechanicsPolarizabilityQuantum mechanicssymbolsNumerical differentiationPhysical and Theoretical ChemistryVDP::Matematikk og Naturvitenskap: 400::Kjemi: 440::Teoretisk kjemi kvantekjemi: 444description
The general theory required for the calculation of analytic third energy derivatives at the coupled-cluster level of theory is presented and connected to preceding special formulations for hyperpolarizabilities and polarizability gradients. Based on our theory, we have implemented a scheme for calculating the dipole Hessian matrix in a fully analytical manner within the coupled-cluster singles and doubles approximation. The dipole Hessian matrix is the second geometrical derivative of the dipole moment and thus a third derivative of the energy. It plays a crucial role in IR spectroscopy when taking into account anharmonic effects and is also essential for computing vibrational corrections to dipole moments. The superior accuracy of the analytic evaluation of third energy derivatives as compared to numerical differentiation schemes is demonstrated in some pilot calculations.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-01-01 |