Fragment-based Time-dependent Density-functional Theory

Abstract

Using the Runge-Gross theorem that establishes the foundation of Time-dependent Density Functional Theory (TDDFT) we prove that for a given electronic Hamiltonian, choice of initial state, and choice of fragmentation, there is a unique single-particle potential (dubbed time-dependent partition potential) which, when added to each of the pre-selected fragment potentials, forces the fragment densities to evolve in such a way that their sum equals the exact molecular density at all times. This uniqueness theorem suggests new ways of computing time-dependent properties of electronic systems via fragment-TDDFT calculations. We derive a formally exact relationship between the partition potential and the total density, and illustrate our approach on a simple model system for binary fragmentation in a laser field.

5 pages, 2 figures

References in corpus (4)

• Time-dependent density functional theory: Past, present, and future
• On the "Causality Paradox" of Time-Dependent Density Functional Theory
• On the Subsystem Formulation of Linear-Response Time-Dependent DFT
• Local Control and v-Representability of Correlated Quantum Dynamics

Cited by in corpus (5)

• The Importance of being consistent
• Existence, Uniqueness, and Construction of the Density-Potential Mapping in Time-Dependent Density-Functional Theory
• Subsystem real-time Time Dependent Density Functional Theory
• Non-Adiabatic Approximations in Time-Dependent Density Functional Theory: Progress and Prospects
• FDE-vdW: A van der Waals Inclusive Subsystem Density-Functional Theory