Selective photo-dissociative ionization of methane molecule with TDDFT study

Area of Science:

• Quantum Chemistry
• Laser Physics
• Chemical Dynamics

Background:

• Controlling molecular dissociation with lasers is crucial for chemical synthesis.
• Accurate theoretical models are needed to design effective laser control strategies.
• Methane (CH4) dissociation presents a complex quantum mechanical challenge.

Purpose of the Study:

• To develop a theoretical framework for optimizing laser fields to control methane dissociation dynamics.
• To predict the outcome of laser-induced dissociation for specific molecular fragments.
• To achieve high dissociation yields for targeted chemical products.

Main Methods:

• Formulation of three-dimensional control dynamics using an iterative method.
• Application of time-dependent density functional theory (TDDFT).
• Design and simulation of tailored laser pulse profiles.

Main Results:

• Predicted tailored laser pulse profiles and eigenstate distributions.
• Obtained exact energy levels for the methane molecule.
• Achieved high dissociation rates: 78% for CH2+, 80% for CH+, 90% for C+, and 82% for C++.

Conclusions:

• The developed iterative and TDDFT approach effectively controls methane dissociation.
• High dissociation yields for specific ions (CH2+, CH+, C+, C++) were demonstrated.
• The presented method provides a pathway to reduce controlling costs in laser-induced chemical reactions.