Analytical energy gradient based on spin-free infinite-order Douglas-Kroll-Hess method with local unitary transformation
Abstract
In this study, the analytical energy gradient for the spin-free infinite-order Douglas-Kroll-Hess (IODKH) method at the levels of the Hartree-Fock (HF), density functional theory (DFT), and second-order Møller-Plesset perturbation theory (MP2) is developed. Furthermore, adopting the local unitary transformation (LUT) scheme for the IODKH method improves the efficiency in computation of the analytical energy gradient. Numerical assessments of the present gradient method are performed at the HF, DFT, and MP2 levels for the IODKH with and without the LUT scheme. The accuracies are examined for diatomic molecules such as hydrogen halides, halogen dimers, coinage metal (Cu, Ag, and Au) halides, and coinage metal dimers, and 20 metal complexes, including the fourth-sixth row transition metals. In addition, the efficiencies are investigated for one-, two-, and three-dimensional silver clusters. The numerical results confirm the accuracy and efficiency of the present method.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- December 2013
- DOI:
- 10.1063/1.4850638
- Bibcode:
- 2013JChPh.139x4107N
- Keywords:
-
- density functional theory;
- halides;
- HF calculations;
- hydrogen compounds;
- metal clusters;
- perturbation theory;
- silver;
- 36.40.Cg;
- 31.15.xp;
- 31.15.E-;
- 31.15.xr;
- Electronic and magnetic properties of clusters;
- Perturbation theory;
- Density-functional theory;
- Self-consistent-field methods