Conditional Wave Function Theory: A Unified Treatment of Molecular Structure and Nonadiabatic Dynamics

Area of Science:

• Quantum mechanics
• Computational chemistry
• Theoretical physics

Background:

• Correlated electron-ion systems present significant challenges in accurately describing their equilibrium structure and dynamics.
• Existing methods often struggle to efficiently handle the complexity of many-body wave functions in these systems.

Purpose of the Study:

• To introduce and validate a novel theoretical framework, conditional wave function theory, for a unified treatment of electron-ion systems.
• To demonstrate the efficiency and accuracy of this theory in capturing both static and dynamic properties.

Main Methods:

• Formulation of a variational wave function ansatz based on conditional wave function slices.
• Application of the theory to determine structural and time-dependent response properties of the hydrogen molecule.
• Extension to time-dependent conditional wave functions to model nonequilibrium processes.

Main Results:

• The conditional wave function theory successfully recasts complex many-body wave functions into simpler, coupled "slices".
• Accurate prediction of structural and time-dependent properties for the hydrogen molecule.
• Successful modeling of complex nonequilibrium phenomena like molecular ionization and proton transfer.

Conclusions:

• Conditional wave function theory provides a powerful and unified tool for ab initio molecular simulations.
• This approach is applicable to both equilibrium and nonequilibrium scenarios for various systems.
• Opens new avenues for simulating complex quantum phenomena in chemistry and physics.