Explicitly correlated plane waves: accelerating convergence in periodic wavefunction expansions.

Area of Science:

• Quantum Chemistry
• Computational Physics

Background:

• Accurate calculation of electronic correlation energy is crucial in quantum chemistry.
• Periodic wavefunction expansions are essential for modeling condensed matter and materials.

Purpose of the Study:

• To investigate explicitly correlated plane wave basis sets for periodic wavefunction expansions.
• To improve the convergence of electronic correlation energy calculations in second-order Møller-Plesset (MP2) theory.

Main Methods:

• Employed second-order Møller-Plesset (MP2) perturbation theory.
• Utilized plane wave basis sets with explicitly correlated geminal factors.
• Introduced and tested a novel Yukawa-Coulomb correlation factor.

Main Results:

• Demonstrated improved convergence of correlation energies with the novel Yukawa-Coulomb factor.
• Showcased the complementary nature of plane waves and short-ranged geminals for periodic systems.
• Achieved rapidly convergent basis for periodic wavefunction descriptions.

Conclusions:

• The combination of plane waves and geminal correlation factors offers an efficient approach for periodic systems.
• This method has the potential to broaden the applicability of discrete wavefunction expansions.
• Enhanced convergence in MP2 calculations for periodic systems was achieved.