Describing proton transfer modes in shared proton systems with constrained nuclear-electronic orbital methods

Area of Science:

• Quantum Chemistry
• Chemical Physics
• Computational Chemistry

Background:

• Proton transfer is fundamental to chemical and biological processes.
• Accurately modeling proton transfer is challenging due to significant nuclear quantum effects.
• Traditional methods like DFT often struggle with shared proton systems.

Purpose of the Study:

• To investigate proton transfer modes in prototypical shared proton systems.
• To evaluate the performance of constrained nuclear-electronic orbital density functional theory (CNEO-DFT) and molecular dynamics (CNEO-MD).
• To compare CNEO methods with standard DFT and ab initio molecular dynamics.

Main Methods:

• Application of constrained nuclear-electronic orbital density functional theory (CNEO-DFT).
• Utilizing constrained nuclear-electronic orbital molecular dynamics (CNEO-MD) for simulations.
• Studying three prototypical shared proton systems.

Main Results:

• CNEO-DFT and CNEO-MD accurately describe the geometries and vibrational spectra of shared proton systems.
• These methods effectively capture nuclear quantum effects crucial for proton transfer.
• Standard DFT and ab initio molecular dynamics showed limitations in describing these systems.

Conclusions:

• CNEO-DFT and CNEO-MD provide reliable descriptions of shared proton systems.
• The accurate inclusion of nuclear quantum effects is key to the success of CNEO methods.
• CNEO-MD is a promising computational tool for future studies of complex proton transfer phenomena.