Numerically exact configuration interaction at quadrillion-determinant scale.

ABSTRACT: The combinatorial growth of configuration interaction (CI) has long limited this formally exact quantum chemistry method to only the smallest molecules. Here, we report a numerically exact CI calculation exceeding one quadrillion (10¹⁵) determinants, made possible by a lossless categorical compression strategy within the small-tensor-product distributed active space (STP-DAS) framework. This approach overcomes the traditional memory bottlenecks of CI by a numerically exact compression of the wavefunction representation and reformulating the most computationally demanding matrix-vector operations. Using this method, we performed a fully relativistic CI calculation of the ground state of HBrTe with over 10¹⁵ complex-valued determinants in just 34.5 h on 1000 computing n

SUBMITTER: Shayit A 

PROVIDER: S-EPMC12696099 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature