Geminal embedding scheme for optimal atomic basis set construction in correlated calculations.

Area of Science:

• Computational Chemistry
• Quantum Mechanics

Background:

• Electronic structure calculations are crucial for understanding material properties.
• Accurate representation of many-body wave functions requires significant computational resources.
• Developing efficient and adaptive basis sets is essential for advancing computational chemistry.

Purpose of the Study:

• To introduce an efficient method for constructing optimal and system-adaptive basis sets.
• To reduce the number of variational parameters in many-body wave function calculations.
• To enable controlled optimization of wave functions for large systems.

Main Methods:

• An embedding scheme is used, isolating a reference atom from its environment.
• The system is described by a Slater determinant or antisymmetrized geminal power (AGP) extension.
• Primitive basis sets are contracted into geminal embedded orbitals (GEOs).
• Variational Monte Carlo with a Jastrow factor is employed for energy minimization.

Main Results:

• A dramatic reduction in variational parameters for a given accuracy was achieved.
• The resulting GEO basis sets facilitate controlled optimization of many-body wave functions.
• The method was applied to the water molecule, cerium volume collapse, and high-pressure liquid hydrogen.

Conclusions:

• The developed method provides an efficient pathway for constructing accurate basis sets.
• This approach is suitable for electronic structure calculations of bulk materials with many electrons and atoms.
• The GEO basis sets offer a significant advancement in computational quantum chemistry.