Accurate quantum molecular dynamics for multidimensional systems by the basis expansion leaping multi-configuration...

Area of Science:

• Quantum Chemistry
• Chemical Dynamics
• Computational Chemistry

Background:

• Quantum phenomena significantly influence chemical reactions.
• Accurate simulation of quantum effects like tunneling is essential for understanding chemical processes.
• Quantum molecular dynamics (QMD) methods are needed to study these effects.

Purpose of the Study:

• To evaluate the applicability of the basis expansion leaping multi-configuration Gaussian (BEL MCG) method for simulating quantum dynamics.
• To investigate the requirements for achieving highly accurate dynamics using the BEL MCG method, particularly for double well problems.
• To highlight key features of BEL MCG propagation for reliable quantum simulations.

Main Methods:

• Development and application of the basis expansion leaping multi-configuration Gaussian (BEL MCG) method.
• Time-propagation of wave packets for reactive molecular systems.
• Examination of BEL MCG performance on multi-dimensional double well problems.

Main Results:

• The BEL MCG method demonstrates applicability to multi-dimensional double well problems.
• Accurate quantum dynamics simulations require careful selection of basis function width.
• The width of Gaussian basis functions must be appropriate for the local potential energy surface.

Conclusions:

• The BEL MCG method is a viable approach for studying quantum effects in chemical reactions.
• Optimizing basis function characteristics is critical for the accuracy of Gaussian-based QMD methods.
• This work provides insights into improving the reliability of quantum molecular dynamics simulations.