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Title: Scalable Ab Initio Electronic Structure Methods with Near Chemical Accuracy for Main Group Chemistry
This study evaluates the precision of widely recognized quantum chemical methodologies, CCSD(T), DLPNO−CCSD(T), and localized ph-AFQMC, for determining the thermochemistry of main group elements. DLPNO−CCSD- (T) and localized ph-AFQMC, which o(er greater scalability compared to canonical CCSD(T), have emerged over the past decade as pivotal in producing precise benchmark chemical data. Our investigation includes closed-shell, neutral molecules, focusing on their heat of formation and atomization energy sourced from four specific small molecule data sets. First, we selected molecules from the G2 and G3 data sets, noted for their reliable experimental heat of formation data. Additionally, we incorporate molecules from the W4−11 and W4−17 sets, which provide high-level theoretical reference values for atomization energy at 0 K. Our findings reveal that both DLPNO−CCSD(T) and ph-AFQMC methods are capable of achieving a root-mean-square deviation of less than 1 kcal/mol across the combined data set, aligning with the threshold for chemical accuracy. Moreover, we make e(orts to confine the maximum deviations within 2 kcal/mol, a degree of precision that significantly broadens the applicability of these methods in fields such as biology and materials science.  more » « less
Award ID(s):
2245592
PAR ID:
10581704
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
The of Physical Chemistry A
Date Published:
Journal Name:
The Journal of Physical Chemistry A
Volume:
128
Issue:
28
ISSN:
1089-5639
Page Range / eLocation ID:
5796 to 5807
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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