We present an efficient algorithm for one- and two-component analytical energy gradients with respect to nuclear displacements in the exact two-component decoupling approach to the one-electron Dirac equation (X2C). Our approach is a generalization of the spin-free ansatz by Cheng and Gauss [J. Chem. Phys. 135, 084114 (2011)], where the perturbed one-electron Hamiltonian is calculated by solving a first-order response equation. Computational costs are drastically reduced by applying the diagonal local approximation to the unitary decoupling transformation (DLU) [D. Peng and M. Reiher, J. Chem. Phys. 136, 244108 (2012)] to the X2C Hamiltonian. The introduced error is found to be almost negligible as the mean absolute error of the optimized structures amounts to only 0.01 pm. Our implementation in TURBOMOLE is also available within the finite nucleus model based on a Gaussian charge distribution. For a X2C/DLU gradient calculation, computational effort scales cubically with the molecular size, while storage increases quadratically. The efficiency is demonstrated in calculations of large silver clusters and organometallic iridium complexes.
Skip Nav Destination
Article navigation
14 March 2018
Research Article|
March 12 2018
Efficient implementation of one- and two-component analytical energy gradients in exact two-component theory
Yannick J. Franzke;
Yannick J. Franzke
a)
1
Institute of Physical Chemistry, Karlsruhe Institute of Technology
, Kaiserstraße 12, 76131 Karlsruhe, Germany
Search for other works by this author on:
Nils Middendorf;
Nils Middendorf
1
Institute of Physical Chemistry, Karlsruhe Institute of Technology
, Kaiserstraße 12, 76131 Karlsruhe, Germany
Search for other works by this author on:
Florian Weigend
Florian Weigend
b)
1
Institute of Physical Chemistry, Karlsruhe Institute of Technology
, Kaiserstraße 12, 76131 Karlsruhe, Germany
2
Institute of Nanotechnology, Karlsruhe Institute of Technology
, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
Search for other works by this author on:
a)
Electronic mail: yannick.franzke@partner.kit.edu
b)
Electronic mail: florian.weigend@kit.edu
J. Chem. Phys. 148, 104110 (2018)
Article history
Received:
January 11 2018
Accepted:
February 21 2018
Citation
Yannick J. Franzke, Nils Middendorf, Florian Weigend; Efficient implementation of one- and two-component analytical energy gradients in exact two-component theory. J. Chem. Phys. 14 March 2018; 148 (10): 104110. https://doi.org/10.1063/1.5022153
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Pay-Per-View Access
$40.00
Citing articles via
DeePMD-kit v2: A software package for deep potential models
Jinzhe Zeng, Duo Zhang, et al.