An open-source framework for analyzing N-electron dynamics. II. Hybrid density functional theory/configuration interaction methodology

4 years ago

An open-source framework for analyzing N-electron dynamics. II. Hybrid density functional theory/configuration interaction methodology

Gunter Hermann, Jean Christophe Tremblay, Vincent Pohl

In this contribution, we extend our framework for analyzing and visualizing correlated many-electron dynamics to non-variational, highly scalable electronic structure method. Specifically, an explicitly time-dependent electronic wave packet is written as a linear combination of N-electron wave functions at the configuration interaction singles (CIS) level, which are obtained from a reference time-dependent density functional theory (TDDFT) calculation. The procedure is implemented in the open-source Python program detCI@ORBKIT, which extends the capabilities of our recently published post-processing toolbox (Hermann et al., J. Comput. Chem. 2016, 37, 1511). From the output of standard quantum chemistry packages using atom-centered Gaussian-type basis functions, the framework exploits the multideterminental structure of the hybrid TDDFT/CIS wave packet to compute fundamental one-electron quantities such as difference electronic densities, transient electronic flux densities, and transition dipole moments. The hybrid scheme is benchmarked against wave function data for the laser-driven state selective excitation in LiH. It is shown that all features of the electron dynamics are in good quantitative agreement with the higher-level method provided a judicious choice of functional is made. Broadband excitation of a medium-sized organic chromophore further demonstrates the scalability of the method. In addition, the time-dependent flux densities unravel the mechanistic details of the simulated charge migration process at a glance. © 2017 Wiley Periodicals, Inc. In this article, we introduce a highly scalable procedure to investigate and visualize many-electron dynamics in strong laser fields. It is implemented in an open-source Python framework which builds up a space of pseudo-CI singles wave functions from a linear-response TDDFT reference. Using these as a basis, our non-variational hybrid method evaluates transition moments of one-electron operators for explicitly time-dependent electronic wave packets. To demonstrate its capabilities and scalability, we use the time-dependent electronic flux density to unravel the mechanistic details of the simulated charge migration in a medium sized dye.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/jcc.24896