Empowering neural network-based quantum Monte Carlo with local pseudopotentials.

Abstract

Neural network-based quantum Monte Carlo (NNQMC), an emerging method for solving many-body quantum systems with high accuracy, has been mainly applied to small systems owing to demanding computation requirements. Here we introduce a framework based on local pseudopotentials to break through such limitation, improving the computational efficiency and scalability of NNQMC. The incorporation of local pseudopotentials reduces the number of electrons treated in neural network and also achieves better relative energy accuracy than all electron NNQMC calculations for complex systems. This counterintuitive outcome is made possible by the distinctive characteristics inherent to NNQMC. Notably, by avoiding costly integration terms, this approach is also substantially more efficient than its widely used semilocal counterparts. Our approach enables the reliable treatment of large and challenging systems, such as the <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <msub><mrow><mi>Fe</mi></mrow> <mrow><mn>4</mn></mrow> </msub> <msub><mrow><mi>S</mi></mrow> <mrow><mn>4</mn></mrow> </msub> <msub> <mrow><mrow><mo>(</mo> <mrow> <msub><mrow><mi>SCH</mi></mrow> <mrow><mn>3</mn></mrow> </msub> </mrow> <mo>)</mo></mrow> </mrow> <mrow><mn>4</mn></mrow> </msub> </mrow> </math> iron-sulfur cluster. Overall, our findings demonstrate that the synergy between NNQMC and local pseudopotentials substantially expands the scope of accurate ab initio calculations.