Journal of Computational Chemistry最新文献

{"title":"Quantification of Reaction Barriers Under Diffusion Controlled Conditions","authors":"Martin M. Maehr,&nbsp;Radu A. Talmazan,&nbsp;Maren Podewitz","doi":"10.1002/jcc.70233","DOIUrl":"https://doi.org/10.1002/jcc.70233","url":null,"abstract":"<p>In quantum chemistry, diffusion-controlled reactions are typically characterized by a monotonous rise in the electronic energy, indicative of a barrierless process. In reality, this change in electronic energy is accompanied by an increase in entropy, thereby introducing a barrier in free energy. Standard quantum-chemical models fall short in capturing this phenomenon, but we have developed a cost-efficient method to address this challenge. By tracking changes in bonding based on quantum chemical descriptors, we can model the onset of entropy along the reaction path by defining a cutoff that indicates the halfway point in the entropy gain. Utilizing a sigmoid fit function to model the entropy change, we obtain a transition state on the free energy surface for diffusion-controlled reactions. Our methodology is robust and suitable for diverse complexes within both organic and inorganic chemistry.</p>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jcc.70233","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145146963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Exploration of Small Hydrocarbon Networks: A Stochastic Generation and DFT Refinement Framework","authors":"Sandip Giri,&nbsp;Sayon Satpati,&nbsp;Tarun Roy,&nbsp;Subhas Ghosal,&nbsp;Anakuthil Anoop","doi":"10.1002/jcc.70236","DOIUrl":"https://doi.org/10.1002/jcc.70236","url":null,"abstract":"<div>\u0000 \u0000 <p>Small hydrocarbons are central to astrochemistry due to their prevalence and chemical reactivity across diverse interstellar environments. Here, we present <b>HydroMol</b>, an open-access computational platform designed for systematic exploration and analysis of hydrocarbon chemical spaces, featuring over 2700 neutral <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mrow>\u0000 <mtext>C</mtext>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>n</mi>\u0000 </mrow>\u0000 </msub>\u0000 <msub>\u0000 <mrow>\u0000 <mtext>H</mtext>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 </mrow>\u0000 </msub>\u0000 <mo>(</mo>\u0000 <mi>n</mi>\u0000 <mo>,</mo>\u0000 <mi>m</mi>\u0000 <mo>=</mo>\u0000 <mn>1</mn>\u0000 <mo>−</mo>\u0000 <mn>10</mn>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$$ {mathrm{C}}_n{mathrm{H}}_mleft(n,m=1-10right) $$</annotation>\u0000 </semantics></math> hydrocarbon structures generated stochastically and refined via density functional theory at B3LYP-D3BJ/def2-SVP level. HydroMol provides detailed molecular geometries, thermodynamic parameters, and electronic properties critical for interpreting astrochemical phenomena and identifying promising observational targets. Our database, hosted within a lightweight client-side web application for rapid search and visualization, introduces approximately 2000 previously unreported hydrocarbons absent in major chemical repositories such as PubChem. Statistical analysis highlights the predominance of structurally simple monocyclic and bicyclic species, characterized by HOMO and LUMO energies centered at approximately <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>6</mn>\u0000 </mrow>\u0000 <annotation>$$ -6 $$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$$ -2 $$</annotation>\u0000 </semantics></math> eV, respectively, and typical HOMO–LUMO gaps around 4–5 eV. The methodology is readily extendable to heavier elements and expanded property datasets, providing a valuable resource for astrochemical modeling, molecular spectroscopy, and computational hydrocarbon discovery. The HydroMol web application is freely accessible at https://hydromol.github.io.</p>\u0000 </div>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145146973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin-Dependence of Dipole Moments of Charged Proteins: Theoretical Foundations and Implications, Revisited","authors":"Islam K. Matar,&nbsp;Chérif F. Matta","doi":"10.1002/jcc.70207","DOIUrl":"10.1002/jcc.70207","url":null,"abstract":"<p>Electric dipole moments are widely employed in structural biology and computational chemistry as global descriptors of macromolecular charge distribution, contributing to the understanding of protein interactions, solvation, and orientation in external fields. However, for systems bearing a nonzero net charge, the dipole moment becomes explicitly dependent on the choice of coordinates origin, a consequence grounded in classical electrostatics and sometimes overlooked in structural analyses. This origin-dependence is particularly relevant in biological systems, as proteins are typically charged at physiological pH which differs from their isoelectric points (pI's). Moreover, coordinate manipulations such as centering and alignment are routinely performed during molecular dynamics simulations, docking, and structural comparisons, potentially altering the calculated dipole moment of charged systems. This study reviews the theory of the changes in the dipole moment of charged macromolecules accompanying displacements of the origin of the coordinates system. The theory is illustrated by numerical examples on representative proteins. Using the classical expression <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mover>\u0000 <mi>μ</mi>\u0000 <mo>→</mo>\u0000 </mover>\u0000 <mo>′</mo>\u0000 </msup>\u0000 <mo>=</mo>\u0000 <mover>\u0000 <mi>μ</mi>\u0000 <mo>→</mo>\u0000 </mover>\u0000 <mo>-</mo>\u0000 <mi>Q</mi>\u0000 <mover>\u0000 <mi>a</mi>\u0000 <mo>→</mo>\u0000 </mover>\u0000 </mrow>\u0000 <annotation>$$ {overrightarrow{mu}}^{prime }=overrightarrow{mu}hbox{-} Qoverrightarrow{a} $$</annotation>\u0000 </semantics></math>, we demonstrate that displacements of the order of a protein's radius of gyration or larger can induce dipoles several hundreds to thousands of debyes. We examine this effect across a range of proteins with varying sizes and identify trends correlating the extent of origin-induced changes with molecular size. These examples highlight the need for standardization in defining coordinate systems in dipole-related analyses. The quantum mechanical status of the dipole moment operator is discussed clarifying that only neutral systems satisfy Dirac's criteria for a true “observable”. Altogether, theory, numerical benchmarks, practical guidelines, and pedagogical insights are presented for reliably calculating and interpreting dipole moments of charged biological macromolecules.</p>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jcc.70207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145134288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acetylene-Linked Phenalenyl Oligomers as a Creative Source of Extended Polyradical Character","authors":"Jhonatas R. Carvalho,&nbsp;Reed Nieman,&nbsp;Adelia J. A. Aquino,&nbsp;Dana Nachtigallová,&nbsp;Hans Lischka","doi":"10.1002/jcc.70240","DOIUrl":"10.1002/jcc.70240","url":null,"abstract":"<div>\u0000 \u0000 <p>Phenalenyl is known for its highly delocalized radical structure, making it a fundamental building block in the construction of polyradical compounds. This study explores how different connection topologies between phenalenyl units via acetylenic bridges modulate the polyradical character, as well as the electronic and magnetic properties of the resulting systems. The connection type depends on the atom occupation pattern of the phenalenyl singly occupied orbital (SOMO). Three types of connections are defined that induce different π conjugation strength. Linear di- and tetra-phenalenyl chains and cyclic tri- and tetra-phenalenyl aggregates have been investigated. High-level multireference averaged coupled cluster (MR-AQCC) calculations were performed to describe the electronic structures of these compounds. The polyradical character of the oligomers is assessed using descriptors such as singlet-triplet splitting, effectively unpaired electrons (<i>N</i>_U). Additionally, the harmonic oscillator model of aromaticity (HOMA), multicenter index (MCI), fluctuation index (FLU), nucleus-independent chemical shifts (NICS (1)), and the anisotropy of the current-induced density (ACID) analysis are employed to characterize the influence of the phenalenyl linkages on aromaticity. Results indicate that bridges enabling stronger interaction between the SOMOs of phenalenyl units lead to a reduction in polyradical character. Aromaticity analysis corroborates these findings, revealing decreased aromaticity in rings where electron interaction occurs through the bridge. On the contrary, choosing bridging types of weak interaction leads to strong open shell character providing candidates for molecular magnetism. A comparison with the predictions of Ovchinnikov's rule is carried out both to rationalize the outcomes of the quantum chemical calculations and to highlight limitations of the rule, particularly in the treatment of quasi-degenerate states.</p>\u0000 </div>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145127384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"K2AlInZ6 (Z = F, Cl, Br) Double Perovskites: Potential Candidates for Optoelectronic and Photovoltaic Devices","authors":"Samah Saidi,&nbsp;Soufyane Belhachi,&nbsp;Sahar Abdalla,&nbsp;Jehan Y. Al-Humaidi,&nbsp;M. W. Iqbal,&nbsp;Muneera S. M. Al-Saleem,&nbsp;Mohammed M. Rahman,&nbsp;Mika Sillanpää,&nbsp;Aravind Kumar,&nbsp;Subhav Singh","doi":"10.1002/jcc.70222","DOIUrl":"10.1002/jcc.70222","url":null,"abstract":"<div>\u0000 \u0000 <p>In this research, K₂AlInZ₆ (Z = F, Cl, Br) are double perovskite compounds with unique and complementary characteristics, rendering them exceptionally appropriate for many modern technological applications. This paper provides a thorough examination of the structural, electronic, elastic, mechanical, optical, and thermodynamic features of K₂AlInZ₆ (Z = F, Cl, Br) double perovskites by first-principles calculations based on density functional theory (DFT). The structural characteristics, encompassing lattice parameters and formation energies, validate the stability of these materials, which exhibit a cubic configuration with the Fm-3m space group. The electronic band structure calculations with the modified Becke-Johnson exchange potential indicate indirect band gaps for K₂AlInZ₆ (Z = F, Cl, Br), with band gaps of 3.73, 2.88, and 2.41 eV for K₂AlInF₆, K₂AlInCl₆, and K₂AlInBr₆, respectively, rendering them viable candidates for optoelectronic applications. The estimated elastic constants, bulk modulus, and shear modulus demonstrate mechanical stability, indicating their suitability for durable and flexible devices. The optical characteristics, including dielectric functions and absorption spectra, exhibit considerable absorption in the ultraviolet range, indicating their potential use in photovoltaic systems. Furthermore, the thermodynamic characteristics are examined by assessing formation energy and Debye temperature. The negative formation energies of these materials signify their strong thermodynamic stability, whereas the Debye temperature analysis elucidates their lattice vibrations and heat capacity, further substantiating their stability and applicability in diverse energy technologies. At 800 K, K₂AlInF₆, K₂AlInCl₆, and K₂AlInBr₆ show Seebeck coefficients of ~150, ~160, and ~135 μV/K, respectively, with <i>κ</i>_e/<i>τ</i> rising to ~4.0–4.75 × 10¹⁴ W/mKs. ZT values peak at ~0.69, ~0.68, and ~0.58, indicating strong thermoelectric potential at high temperatures.</p>\u0000 </div>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145117112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability and Reactivity of \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 TiO\u0000 2\u0000 \u0000 \u0000 n\u0000 \u0000 \u0000 $$ {left({mathrm{TiO}}_2right)}_n $$\u0000 , n = 1–10, Clusters and Their Interactions With \u0000 \u0000 \u0000 \u0000 CO\u0000 2\u0000 \u0000 \u0000 $$ {mathrm{CO}}_2 $$","authors":"Letícia Carolaine Silva Faria,&nbsp;Letícia Marques de Souza Vetrano de Queiroz,&nbsp;Murielly Fernanda Ribeiro Bihain,&nbsp;Douglas Henrique Pereira,&nbsp;Leonardo Tsuyoshi Ueno,&nbsp;Francisco Bolivar Correto Machado,&nbsp;Luiz Fernando de Araujo Ferrão","doi":"10.1002/jcc.70232","DOIUrl":"10.1002/jcc.70232","url":null,"abstract":"&lt;p&gt;Small titanium dioxide clusters &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;TiO&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;mi&gt;n&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {left({mathrm{TiO}}_2right)}_n $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; (with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;n&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ n $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; = 1–10) are promising photocatalysts for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CO&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{CO}}_2 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; conversion; however, their size-dependent stability and reactivity are not fully characterized. This study uses density functional theory (M06/def2-TZVP) and global and local reactivity descriptors to identify “magic number” clusters that exhibit high stability. The stability function (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;ε&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {varepsilon}^3 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;), reveals &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;n&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ n $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; = 2, 4, and 8 as magic numbers. Electrophilicity analysis (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;ω&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ Delta omega $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) shows moderate electrophilicity for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;n&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ n $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; = 1–5 and strong electrophilicity for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;n&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ n $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; = 7–10, while the magic numbers display reduced reactivity. Fukui functions and fractional occupation number-weighted density (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 ","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jcc.70232","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leveraging the Bias-Variance Tradeoff in Quantum Chemistry for Accurate Negative Singlet-Triplet Gap Predictions: A Case for Double-Hybrid DFT","authors":"Atreyee Majumdar,&nbsp;Raghunathan Ramakrishnan","doi":"10.1002/jcc.70228","DOIUrl":"10.1002/jcc.70228","url":null,"abstract":"&lt;p&gt;Molecules that have been suggested to violate the Hund's rule, having a first excited singlet state (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;S&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{S}}_1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) energetically below the triplet state (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;T&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{T}}_1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;), are rare. Yet, they hold the promise to be efficient light emitters. Their high-throughput identification demands exceptionally accurate excited-state modeling to minimize qualitatively wrong predictions. We benchmark twelve &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;S&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;T&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{S}}_1-{mathrm{T}}_1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; energy gaps to find that the local-correlated versions of ADC(2) and CC2 excited state methods deliver excellent accuracy and speed for screening medium-sized molecules. Notably, we find that double-hybrid DFT approximations (e.g., B2GP-PLYP and PBE-QIDH) exhibit high mean absolute errors (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mn&gt;100&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mtext&gt;meV&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ &gt;100kern0.3em mathrm{meV} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) despite very low standard deviations (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;≈&lt;/mo&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mtext&gt;meV&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 ","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445263/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145079101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accelerating RESP Charge Calculation With Density Fitting","authors":"Huimin Zhang,&nbsp;Yingfeng Zhang","doi":"10.1002/jcc.70237","DOIUrl":"10.1002/jcc.70237","url":null,"abstract":"<div>\u0000 \u0000 <p>Despite the widespread success of the restrained electrostatic potential (RESP) method in molecular simulations, its high computational cost due to dense molecular electrostatic potential (MEP) sampling limits its application in large-scale systems. Here we present DF-RESP, which combines the density fitting MEP (DF-MEP) method with RESP charge derivation to dramatically accelerate calculations while maintaining accuracy. Compared to conventional RESP calculations, DF-RESP achieves excellent accuracy with a mean absolute error (MAE) in charges below 0.003 e for the S22 benchmark and electrostatic interaction energy deviations under 0.1 kcal/mol. For androgen receptor–ligand complexes, DF-RESP achieves an MAE of less than 0.06 kcal/mol. Notably, DF-RESP precisely captures conformational energy variations in Ser-Ala-Gly tripeptide dynamics through charge analysis and achieves a 14-fold speedup for the 1493-atom protein 1h59 while maintaining comparable accuracy. These results demonstrate that DF-RESP is a computationally efficient and reliable approach for RESP charge calculations in large-scale biomolecular simulations.</p>\u0000 </div>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring Lead-Free Ca3BiCl3-Based Perovskite Solar Cells: A Computational Comparison of Charge Transport Layers With DFT and SCAPS-1D","authors":"Bipul Chandra Biswas,&nbsp;Asadul Islam Shimul,&nbsp;Avijit Ghosh,&nbsp;Nasser S. Awaad,&nbsp;Hala A. Ibrahium","doi":"10.1002/jcc.70231","DOIUrl":"10.1002/jcc.70231","url":null,"abstract":"<div>\u0000 \u0000 <p>Calcium bismuth chloride (Ca₃BiCl₃), an accessible and nontoxic chemical, exhibits considerable promise as a photovoltaic absorber material. This research investigates the structural, optical, and electrical properties of Ca₃BiCl₃ utilizing the CASTEP module in the context of density functional theory (DFT). To enhance the photovoltaic efficacy of Ca₃BiCl₃-based solar cells (SCs), two hole transport layers (HTLs), Spiro-OMeTAD and P3HT, and two electron transport layers (ETLs), C₆₀ and WS₂, were investigated. The Solar Cell Capacitance Simulator (SCAPS-1D) was utilized to undertake a comprehensive numerical analysis of Ca₃BiCl₃ SCs, employing essential semiconductor equations such as Poisson's equation, the carrier continuity equations, and the drift-diffusion model. A comprehensive parameter analysis was performed, including factors such as layer thickness, doping density, temperature, carrier production and recombination rates, defect densities at the interfaces and the bulk material, quantum efficiency, and series vs. shunt resistance. After optimizing the ETL and HTL settings, a maximum power conversion efficiency (PCE) of 27.54% was attained using WS₂ as the ETL and P3HT as the HTL. This arrangement produced a short-circuit current density (<i>J</i>_SC) of 23.393 mA/cm², an open-circuit voltage (<i>V</i>_OC) of 1.313 V, and a fill factor (FF) of 89.64%. The results highlight the significant potential of Ca₃BiCl₃ as an effective absorber material, especially in conjunction with WS₂ and P3HT, for the progression of high-efficiency perovskite heterostructure SCs.</p>\u0000 </div>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Exchange Interactions: Mechanistic Insights and Understanding Orbital Influences in Organic Diradicals","authors":"Chumuiria Debbarma,&nbsp;Debojit Bhattacharya,&nbsp;Suranjan Shil","doi":"10.1002/jcc.70230","DOIUrl":"10.1002/jcc.70230","url":null,"abstract":"<div>\u0000 \u0000 <p>Frontier molecular orbitals play a crucial role in determining the magnetic behavior and exchange interactions in organic radicals. In this study, we investigate the underlying mechanism influencing the need for orbital planarity and the role of frontier orbital overlap in magnetic exchange interactions. To study this, we designed a series of 12 polyacene-coupled triarylmethyl diradicals, systematically increasing in length of polyacene. We have used nine different DFT functionals for the calculation of the magnetic exchange coupling constant (<i>J</i>). The calculation of magnetic exchange coupling reveals that the GGA functionals define a more accurate spin state, hence more correct magnetic behavior than the meta-GGA and hybrid functionals. We have studied the effect of orbital orientation and their energy gap to understand the high magnetic exchange coupling in the higher polyacene-coupled diradicals. Our calculations revealed that the planarity and overlap of the frontier molecular orbitals are one of the key factors in influencing the strength and behavior of the magnetic exchange interactions in diradicals. Specifically, the overlap between SOMOs and LUMO influences the strength of the magnetic exchange interaction.</p>\u0000 </div>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"46 25","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}