Variational perturbation theory for dynamic polarizabilities and dispersion coefficients

Area of Science:

• Atomic physics
• Quantum chemistry
• Computational physics

Background:

• Calculating atomic properties like polarizabilities and dispersion coefficients is crucial for understanding atomic interactions.
• Traditional methods, such as sum-over-states, can be computationally intensive.
• Developing efficient and accurate computational methods is an ongoing challenge in atomic physics.

Purpose of the Study:

• To propose an efficient computational method based on variational perturbation theory (VPT) for calculating atomic dynamic polarizabilities and interatomic dispersion coefficients.
• To verify the accuracy of the proposed VPT method by comparing its results with established methods.
• To investigate the effects of plasma screening on these atomic properties for embedded atoms.

Main Methods:

• The study employs variational perturbation theory (VPT) to calculate atomic properties.
• The method requires only the system's ground-state wave function and radial mean values.
• The VPT method was verified using one- and two-electron atoms and compared against the sum-over-states method.

Main Results:

• The VPT method demonstrated good agreement with sophisticated sum-over-states calculations for simple atoms.
• The method was successfully applied to study Z-scaling laws in the He isoelectronic sequence.
• The VPT method accurately predicted static and dynamic polarizabilities and dispersion coefficients for plasma-embedded atoms across various screening parameters.

Conclusions:

• The developed VPT method provides an efficient and accurate approach for calculating atomic polarizabilities and dispersion coefficients.
• The method is advantageous due to its minimal computational requirements (ground state information only).
• The VPT method effectively captures the influence of plasma screening on the properties of embedded atoms.