{"title":"Basis Set Convergence and Empirical Approaches for Obtaining Accurate Diagonal Born-Oppenheimer Corrections from an Extensive Database of 200 Structurally Diverse Hydrocarbons.","authors":"Amir Karton","doi":"10.1021/acs.jpca.5c02680","DOIUrl":"10.1021/acs.jpca.5c02680","url":null,"abstract":"<p><p>The Born-Oppenheimer (BO) approximation is fundamental to computational chemistry because it drastically simplifies the time-independent Schrödinger equation, making calculations for molecular systems computationally feasible. Accurate determination of the diagonal Born-Oppenheimer correction (DBOC) is essential for achieving benchmark accuracy in high-level thermochemical applications. Here, we establish the DBOC200HC database, consisting of 200 structurally diverse hydrocarbons with up to 18 carbon atoms (e.g., triamantane (C<sub>18</sub>H<sub>24</sub>)), including aliphatic, aromatic, antiaromatic, cyclic, noncyclic, and caged systems. Reference DBOCs are determined near the coupled-cluster singles and doubles complete basis set limit (CCSD/CBS) using additivity schemes based on HF/cc-pVQZ and CCSD/cc-pVnZ (n = D, T) calculations. Given the computational expense associated with CCSD/CBS calculations for large hydrocarbons, it is important to develop reliable yet computationally economical approximations. Several such approaches are assessed using the DBOC200HC database. While scaled Hartree-Fock methods offer limited improvement, methods incorporating first-order Møller-Plesset perturbation theory (MP1) perform significantly better. Specifically, calculating the DBOC at the MP1/cc-pVDZ level of theory and scaling the MP1 correlation component (Δ<i>E</i><sub>DBOC</sub><sup>MP1</sup> = <i>E</i><sub>DBOC</sub><sup>MP1</sup> - <i>E</i><sub>DBOC</sub><sup>HF</sup>) by an empirical factor of 1.5447 yields the best balance between accuracy (RMSD = 0.026 kJ/mol) and computational cost (practically the same cost as HF/cc-pVDZ). This exceptionally low RMSD suggests that highly accurate DBOCs for use in high-level thermochemical protocols can be obtained via the scaled MP1 approach, without resorting to computationally more demanding levels of theory such as MP2 or CCSD. To validate our results, we further test the empirical methods optimized over the DBOC200HC database on an independent database of 12 larger hydrocarbons, including systems like dodecahedrane (CH)<sub>20</sub>.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"5692-5699"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Geometric Guidance Integrated with Directed Electrostatics Strategy within a Graph Neural Network Approach for Nanocluster Structure Prediction.","authors":"Sridatri Nandy, K V Jovan Jose","doi":"10.1021/acs.jpca.5c02284","DOIUrl":"10.1021/acs.jpca.5c02284","url":null,"abstract":"<p><p>We introduce the Geometric-DESIGNN method, which integrates Geometric Guidance with Directed Electrostatics Strategy within a Graph Neural Network framework to predict the stable configuration of nanoclusters on their potential energy surfaces. This approach merges the geometric and electronic strategies using graph neural network-based models to predict structures of large atomic clusters with specific size and point-group symmetries. This approach aids in constructing atomic metal cluster structures by predicting building frames through a geometric approach and locating the minima in the molecular electrostatic potential (MESP) landscape. By following alternate geometric and DESIGNN building strategies for each shell of parent clusters, we efficiently achieve close-packed daughter structures along their evolutionary paths. The geometric-DESIGNN approach is validated on the prototype Mg<sub><i>n</i></sub> clusters, by building structures for sizes up to <i>n</i> < 561. Furthermore, constraining the point-group symmetry of the parent clusters, we identify new symmetric isomers of medium to large Mg<sub><i>n</i></sub> clusters with <i>n</i> < 150. This methodology is also employed to construct stable Mg<sub><i>n</i></sub> nanoclusters with <i>n</i> = 332, 338, and 561. Benchmarking results show that the geometric-DESIGNN approach is an efficient tool for accelerated prediction of the nanocluster structure.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"5671-5682"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ryan P. Brady, Luke R. O’Connor, Rachel A. Dziatko, Justin R. DeFrancisco and Arthur E. Bragg*,
{"title":"","authors":"Ryan P. Brady, Luke R. O’Connor, Rachel A. Dziatko, Justin R. DeFrancisco and Arthur E. Bragg*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 25","pages":"XXX-XXX 2305–2315"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c00903","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander W. Narkiewicz-Jodko, Sean W. Parsons, Hansuja Chaurasia, Stephen L. Coy and Stephen Drucker*,
{"title":"","authors":"Alexander W. Narkiewicz-Jodko, Sean W. Parsons, Hansuja Chaurasia, Stephen L. Coy and Stephen Drucker*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 25","pages":"XXX-XXX 2305–2315"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c02355","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanan Liu, Jai Khatri, Shameemah Thawoos, Nicolas Suas-David and Arthur G. Suits*,
{"title":"","authors":"Yanan Liu, Jai Khatri, Shameemah Thawoos, Nicolas Suas-David and Arthur G. Suits*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 25","pages":"XXX-XXX 2305–2315"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c02265","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Connah J. Harris, Beatrice S. L. Collins and Andrew J. Orr-Ewing*,
{"title":"","authors":"Connah J. Harris, Beatrice S. L. Collins and Andrew J. Orr-Ewing*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 25","pages":"XXX-XXX 2305–2315"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c02679","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Diagrammatic Simplification of Linearized Coupled Cluster Theory.","authors":"Kevin Carter-Fenk","doi":"10.1021/acs.jpca.5c03203","DOIUrl":"10.1021/acs.jpca.5c03203","url":null,"abstract":"<p><p>Linearized Coupled Cluster Doubles (LinCCD) often provides near-singular energies in small-gap systems that exhibit static correlation. This has been attributed to the lack of quadratic <i>T̂</i><sub>2</sub><sup>2</sup> terms that typically balance out small energy denominators in the CCD amplitude equations. Herein, I show that exchange contributions to ring and crossed-ring contractions (not small denominators <i>per se</i>) cause the divergent behavior of LinCC(S)D approaches. Rather than omitting exchange terms, I recommend a regular and size-consistent method that retains only linear ladder diagrams. As LinCCD and configuration interaction doubles (CID) equations are isomorphic, this also implies that simplification (rather than quadratic extensions) of CID amplitude equations can lead to a size-consistent theory. Linearized ladder CCD (LinLCCD) is robust in statically correlated systems and can be made <math><mi>O</mi><mrow><mo>(</mo><msubsup><mi>n</mi><mi>occ</mi><mn>4</mn></msubsup><msubsup><mi>n</mi><mi>vir</mi><mn>2</mn></msubsup><mo>)</mo></mrow></math> with a hole-hole approximation. The results presented here show that LinLCCD and its hole-hole approximation can accurately capture energy differences, even outperforming full CCD and CCSD for noncovalent interactions in small-to-medium sized molecules, setting the stage for further adaptations of these approaches that incorporate more dynamical correlation.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}