Time-dependent multiconfiguration self-consistent-field method based on the occupation-restricted multiple-active-space model for multielectron dynamics in intense laser fields
Year: 2015
Type: article
Abstract: The time-dependent multiconfiguration self-consistent-field method based on the occupation-restricted multiple-active-space model is proposed (TD-ORMAS) for multielectron dynamics in intense laser fields. Extending the previously proposed time-dependent complete-active-space self-consistent-field method [TD-CASSCF; Phys. Rev. A 88, 023402 (2013)], which divides the occupied orbitals into core and active orbitals, the TD-ORMAS method further subdivides the active orbitals into an arbitrary number of subgroups and poses the occupation restriction by giving the minimum and maximum number of electrons distributed in each subgroup. This enables highly flexible construction of the configuration-interaction (CI) space, allowing a large-active-space simulation of dynamics, e.g., the core excitation or ionization. The equations of motion for both CI coefficients and spatial orbitals are derived based on the time-dependent variational principle, and an efficient algorithm is proposed to solve for the orbital time derivatives. In-depth descriptions of the computational implementation are given in a readily programmable manner. The numerical application to the one-dimensional lithium hydride cluster models demonstrates that the high flexibility of the TD-ORMAS framework allows for the cost-effective simulations of multielectron dynamics by exploiting systematic series of approximations to the TD-CASSCF method.
Source: Physical Review A
Authors: Takeshi Sato, Kenichi L. Ishikawa
Institution: The University of Tokyo
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: Theoretical study on attosecond and femtosecond atomic photoionization, G4433069426, G5090614404, G6457224871, G6512227484, Analysis of multielectron dynamics in intense laser fields, Multielectron dynamics in intense laser fields: time-dependent multiconfiguration wavefunction theory, G8921332992
OpenAlex ID: W1979975612