FCIQMC-CASPT2 with Imaginary-Time-Averaged Wave Functions.

• Tác giả: Ali Alavi, Robert J Anderson, Giovanni Li Manni, Arta A Safari
• Ngôn ngữ: eng
• Ký hiệu phân loại: 627.12 Rivers and streams
• Thông tin xuất bản: United States : Journal of chemical theory and computation , 2025
• Bộ sưu tập: NCBI
• ID: 60698

Tóm tắt

A new method to perform complete active space second-order perturbation theory on top of large active spaces optimized with full configuration quantum Monte Carlo is presented. Computing the three- and Fock-contracted four-particle density matrix from imaginary-time-averaged wave functions is found to resolve fermionic positivity violations and to ensure numerical stability. The protocol is applied to [NiFe]-hydrogenase, [Cu