Orbital optimization of large active spaces via AI-accelerators

Fuente: arXiv
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Main Authors: Legeza, Örs, Menczer, Andor, Ganyecz, Ádám, Werner, Miklós Antal, Kapás, Kornél, Hammond, Jeff, Xantheas, Sotiris S., Ganahl, Martin, Neese, Frank
Format: Preprint
Published: 2025
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author Legeza, Örs
Menczer, Andor
Ganyecz, Ádám
Werner, Miklós Antal
Kapás, Kornél
Hammond, Jeff
Xantheas, Sotiris S.
Ganahl, Martin
Neese, Frank
author_facet Legeza, Örs
Menczer, Andor
Ganyecz, Ádám
Werner, Miklós Antal
Kapás, Kornél
Hammond, Jeff
Xantheas, Sotiris S.
Ganahl, Martin
Neese, Frank
contents We present an efficient orbital optimization procedure that combines the highly GPU accelerated, spin-adapted density matrix renormalization group (DMRG) method with the complete active space self-consistent field (CAS-SCF) approach for quantum chemistry implemented in the ORCA program package. Leveraging the computational power of the latest generation of Nvidia GPU hardware, we perform CAS-SCF based orbital optimizations for unprecedented CAS sizes of up to 82 electrons in 82 orbitals [CAS(82,82)] in molecular systems comprising of active spaces sizes of hundreds of electrons in thousands of orbitals. For both the NVIDIA DGX-A100 and DGX-H100 hardware, we provide a detailed scaling and error analysis of our DMRG-SCF approach for benchmark systems consisting of polycyclic aromatic hydrocarbons and iron-sulfur complexes of varying sizes. Our efforts demonstrate for the first time that highly accurate DMRG calculations at large bond dimensions are critical for obtaining reliably converged CAS-SCF energies. For the more challenging iron-sulfur benchmark systems, we furthermore find the optimized orbitals of a converged CAS-SCF calculation to depend more sensitively on the DMRG parameters than those for the polycyclic aromatic hydrocarbons. The ability to obtain converged CAS-SCF energies and orbitals for active spaces of such large sizes within days reduces the challenges of including the appropriate orbitals into the CAS or selecting the correct minimal CAS, and may open up entirely new avenues for tackling strongly correlated molecular systems.
format Preprint
id arxiv_https___arxiv_org_abs_2503_20700
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Orbital optimization of large active spaces via AI-accelerators
Legeza, Örs
Menczer, Andor
Ganyecz, Ádám
Werner, Miklós Antal
Kapás, Kornél
Hammond, Jeff
Xantheas, Sotiris S.
Ganahl, Martin
Neese, Frank
Chemical Physics
Strongly Correlated Electrons
We present an efficient orbital optimization procedure that combines the highly GPU accelerated, spin-adapted density matrix renormalization group (DMRG) method with the complete active space self-consistent field (CAS-SCF) approach for quantum chemistry implemented in the ORCA program package. Leveraging the computational power of the latest generation of Nvidia GPU hardware, we perform CAS-SCF based orbital optimizations for unprecedented CAS sizes of up to 82 electrons in 82 orbitals [CAS(82,82)] in molecular systems comprising of active spaces sizes of hundreds of electrons in thousands of orbitals. For both the NVIDIA DGX-A100 and DGX-H100 hardware, we provide a detailed scaling and error analysis of our DMRG-SCF approach for benchmark systems consisting of polycyclic aromatic hydrocarbons and iron-sulfur complexes of varying sizes. Our efforts demonstrate for the first time that highly accurate DMRG calculations at large bond dimensions are critical for obtaining reliably converged CAS-SCF energies. For the more challenging iron-sulfur benchmark systems, we furthermore find the optimized orbitals of a converged CAS-SCF calculation to depend more sensitively on the DMRG parameters than those for the polycyclic aromatic hydrocarbons. The ability to obtain converged CAS-SCF energies and orbitals for active spaces of such large sizes within days reduces the challenges of including the appropriate orbitals into the CAS or selecting the correct minimal CAS, and may open up entirely new avenues for tackling strongly correlated molecular systems.
title Orbital optimization of large active spaces via AI-accelerators
topic Chemical Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2503.20700