Related Experiment Video
Updated: Apr 11, 2026

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Orbital free DFT versus single density equation: a perspective through quantum domain behavior of a classically
Debdutta Chakraborty1, Susmita Kar1, Pratim Kumar Chattaraj1
1Department of Chemistry and Centre for Theoretical Studies, Indian Institute of Technology, Kharagpur 721302, West Bengal, India. pkc@chem.iitkgp.ernet.in.
Abstract:
The orbital free density functional theory and the single density equation approach are formally equivalent. An orbital free density based quantum dynamical strategy is used to study the quantum-classical correspondence in both weakly and strongly coupled van der Pol and Duffing oscillators in the presence of an external electric field in one dimension. The resulting quantum hydrodynamic equations of motion are solved through an implicit Euler type real space method involving a moving weighted least square technique. The Lagrangian framework used here allows the numerical grid points to follow the wave packet trajectory. The associated classical equations of motion are solved using a sixth order Runge-Kutta method and the Ehrenfest dynamics is followed through the solution of the time dependent Schrodinger equation using a time dependent Fourier Grid Hamiltonian technique. Various diagnostics reveal a close parallelism between classical regular as well as chaotic dynamics and that obtained from the Bohmian mechanics.
Related Concept Videos
Atomic Orbitals
The Quantum-Mechanical Model of an Atom
Molecular Orbital Theory I
First Law: Particles in One-dimensional Equilibrium
First Law: Particles in Two-dimensional Equilibrium
Newton's first law tells us about...
Molecular Orbital Theory II

