An accurate description of the long-range (LR) interaction is essential for understanding the collision between cold or ultracold molecules. However, to our best knowledge, there lacks a general approach to construct the intermolecular potential energy surface (IPES) between two arbitrary molecules and/or atoms in the LR region. In this work, we derived analytical expressions of the LR interaction energy, using the multipole expansion of the electrostatic interaction Hamiltonian and the non-degenerate perturbation theory. To make these formulae practical, we also derived the independent Cartesian components of the electrostatic properties, including the multipole moments and polarizabilities, of the monomer for a given symmetry using the properties of these components and the group-theoretical methods. Based on these newly derived formulae, we developed a FORTRAN program, namely ABLRI, which is capable of calculating the interaction energy between two arbitrary monomers both in their non-degenerate electronic ground states at large separations. To test the reliability of this newly developed program, we constructed IPESs for the electronic ground state of H2O–H2 and O2–H systems in the LR region. The interaction energy computed by our program agreed well with the ab initio calculation, which shows the validity of this program.
准确描述长程（LR）相互作用对于理解冷分子或超冷分子之间的碰撞至关重要。然而，据我们所知，目前还缺乏一种通用方法来构建两个任意分子和/或原子之间在长程作用区域的分子间势能面（IPES）。在这项工作中，我们利用静电相互作用哈密顿的多极扩展和非退化扰动理论，推导出了 LR 相互作用能的分析表达式。为了使这些公式实用化，我们还利用这些分量的性质和群论方法，推导出了给定对称性下单体静电性质的独立笛卡尔分量，包括多极矩和极化率。根据这些新推导出的公式，我们开发了一个 FORTRAN 程序，即 ABLRI，该程序能够计算两个任意单体在大间隔非退化电子基态下的相互作用能。为了测试这一新开发程序的可靠性，我们构建了 H2O-H2 和 O2-H 系统在 LR 区域的电子基态 IPES。我们的程序计算出的相互作用能与 ab initio 计算结果非常吻合，这表明了该程序的有效性。
{"title":"ABLRI: A program for calculating the long-range interaction energy between two monomers in their non-degenerate states","authors":"Yipeng Yu, Dongzheng Yang, Xixi Hu, Daiqian Xie","doi":"10.1063/5.0205486","DOIUrl":"https://doi.org/10.1063/5.0205486","url":null,"abstract":"An accurate description of the long-range (LR) interaction is essential for understanding the collision between cold or ultracold molecules. However, to our best knowledge, there lacks a general approach to construct the intermolecular potential energy surface (IPES) between two arbitrary molecules and/or atoms in the LR region. In this work, we derived analytical expressions of the LR interaction energy, using the multipole expansion of the electrostatic interaction Hamiltonian and the non-degenerate perturbation theory. To make these formulae practical, we also derived the independent Cartesian components of the electrostatic properties, including the multipole moments and polarizabilities, of the monomer for a given symmetry using the properties of these components and the group-theoretical methods. Based on these newly derived formulae, we developed a FORTRAN program, namely ABLRI, which is capable of calculating the interaction energy between two arbitrary monomers both in their non-degenerate electronic ground states at large separations. To test the reliability of this newly developed program, we constructed IPESs for the electronic ground state of H2O–H2 and O2–H systems in the LR region. The interaction energy computed by our program agreed well with the ab initio calculation, which shows the validity of this program.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140827905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The task of a first principles theoretical calculation of the rate of gas–liquid nucleation has remained largely incomplete despite the existence of reliable results from unbiased simulation studies at large supersaturation. Although the classical nucleation theory formulated by Becker–Doring–Zeldovich about a century ago provides an elegant, widely used picture of nucleation in a first-order phase transition, the theory finds difficulties in predicting the rate accurately, especially in the case of gas-to-liquid nucleation. Here, we use a multiple-order parameter description to construct the nucleation free energy surface needed to calculate the nucleation rate. A multidimensional non-Markovian (MDNM) rate theory formulation that generalizes Langer’s well-known nucleation theory by using the Grote–Hynes MDNM treatment is used to obtain the rate of barrier crossing. We find good agreement of the theory with the rate obtained by direct unbiased molecular dynamics simulations—the latter is feasible at large supersaturation, S. The theory gives an experimentally strong dependence of the rate of nucleation on supersaturation, S. Interestingly, we find a strong influence of the frequency-dependent friction coefficient at the barrier top. This arises from multiple recrossings of the barrier surface. We find that a Markovian theory, such as Langer’s formulation, fails to capture the rate quantitatively. In addition, the multidimensional transition state theory expression performs poorly, revealing the underlying role of the friction coefficient.
尽管在大过饱和度条件下进行的无偏模拟研究已经取得了可靠的结果，但对气液成核速率进行第一性原理理论计算的任务在很大程度上仍未完成。尽管贝克尔-多林-泽尔多维奇（Becker-Doring-Zeldovich）在大约一个世纪前提出的经典成核理论为一阶相变中的成核提供了一个优雅的、被广泛使用的图景，但该理论在准确预测速率方面存在困难，尤其是在气-液成核的情况下。在这里，我们使用多阶参数描述来构建计算成核率所需的成核自由能面。多维非马尔可夫（MDNM）速率理论表述通过使用格罗特-海因斯 MDNM 处理方法对兰格著名的成核理论进行了概括，从而获得了越障速率。我们发现该理论与通过直接无偏分子动力学模拟获得的速率非常吻合--后者在高过饱和度 S 条件下是可行的。这源于阻挡层表面的多次重越。我们发现马尔可夫理论（如朗格公式）无法定量捕捉这一速率。此外，多维过渡态理论表达也表现不佳，揭示了摩擦系数的潜在作用。
{"title":"Rate theory of gas–liquid nucleation: Quest for the elusive quantitative accuracy","authors":"Subhajit Acharya, Biman Bagchi","doi":"10.1063/5.0202884","DOIUrl":"https://doi.org/10.1063/5.0202884","url":null,"abstract":"The task of a first principles theoretical calculation of the rate of gas–liquid nucleation has remained largely incomplete despite the existence of reliable results from unbiased simulation studies at large supersaturation. Although the classical nucleation theory formulated by Becker–Doring–Zeldovich about a century ago provides an elegant, widely used picture of nucleation in a first-order phase transition, the theory finds difficulties in predicting the rate accurately, especially in the case of gas-to-liquid nucleation. Here, we use a multiple-order parameter description to construct the nucleation free energy surface needed to calculate the nucleation rate. A multidimensional non-Markovian (MDNM) rate theory formulation that generalizes Langer’s well-known nucleation theory by using the Grote–Hynes MDNM treatment is used to obtain the rate of barrier crossing. We find good agreement of the theory with the rate obtained by direct unbiased molecular dynamics simulations—the latter is feasible at large supersaturation, S. The theory gives an experimentally strong dependence of the rate of nucleation on supersaturation, S. Interestingly, we find a strong influence of the frequency-dependent friction coefficient at the barrier top. This arises from multiple recrossings of the barrier surface. We find that a Markovian theory, such as Langer’s formulation, fails to capture the rate quantitatively. In addition, the multidimensional transition state theory expression performs poorly, revealing the underlying role of the friction coefficient.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"118 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140837368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A proof-of-concept study is undertaken to demonstrate the utility of the machine learning combined with the thermodynamic perturbation theory (MLPT) to test the accuracy of electronic structure methods in finite-temperature thermodynamic calculations. As a test example, formic acid dimer is chosen, which is one of the systems included in the popular benchmark set S22 [Jurečka et al., Phys. Chem. Chem. Phys. 8, 1985–1993 (2006)]. Starting from the explicit molecular dynamics and thermodynamic integration performed at the PBE + D2 level, the MLPT is used to obtain fully anharmonic dimerization free and internal energies at the reference quality CCSD(T) level and 19 different density functional approximations, including GGA, meta-GGA, non-local, and hybrid functionals with and without dispersion corrections. Our finite-temperature results are shown to be both qualitatively and quantitatively different from those obtained using the conventional benchmarking strategy based on fixed structures. The hybrid functional HSE06 is identified as the best performing approximate method tested, with the errors in free and internal energies of dimerization being 36 and 41 meV, respectively.
{"title":"Thermodynamics of the gas-phase dimerization of formic acid: Fully anharmonic finite temperature calculations at the CCSD(T) and many DFT levels","authors":"Dávid Vrška, Michal Pitoňák, Tomáš Bučko","doi":"10.1063/5.0205448","DOIUrl":"https://doi.org/10.1063/5.0205448","url":null,"abstract":"A proof-of-concept study is undertaken to demonstrate the utility of the machine learning combined with the thermodynamic perturbation theory (MLPT) to test the accuracy of electronic structure methods in finite-temperature thermodynamic calculations. As a test example, formic acid dimer is chosen, which is one of the systems included in the popular benchmark set S22 [Jurečka et al., Phys. Chem. Chem. Phys. 8, 1985–1993 (2006)]. Starting from the explicit molecular dynamics and thermodynamic integration performed at the PBE + D2 level, the MLPT is used to obtain fully anharmonic dimerization free and internal energies at the reference quality CCSD(T) level and 19 different density functional approximations, including GGA, meta-GGA, non-local, and hybrid functionals with and without dispersion corrections. Our finite-temperature results are shown to be both qualitatively and quantitatively different from those obtained using the conventional benchmarking strategy based on fixed structures. The hybrid functional HSE06 is identified as the best performing approximate method tested, with the errors in free and internal energies of dimerization being 36 and 41 meV, respectively.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"107 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140827653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Denninger, H. Brunst, L. J. G. W. van Wilderen, M. Horz, H. M. A. Masood, C. D. McNitt, I. Burghardt, V. V. Popik, J. Bredenbeck
Click chemistry refers to selective reactions developed for grafting of bio(macro)molecules in their biological media. Caged click compounds have been employed to spatiotemporally control click reactions. Here, we survey the uncaging of photo-dibenzocyclooctyne-OH (photoDIBO-OH) to its click-chemistry active form DIBO-OH, with particular attention to its conversion timescale and efficiency. Ultraviolet pump–infrared probe experiments reveal a stepwise decarbonylation: first, carbon monoxide (C≡O) is released within 1.8 ps, and then, it converts, within 10 ps, to DIBO-OH. Completion of uncaging is achieved with an efficiency of ∼50%. A successful demonstration of two-photon uncaging of photoDIBO-OH at long wavelength (700 nm) confers enhanced in vivo compatibility and proceeds on the same timescale.
{"title":"Switch the click: Ultrafast photochemistry of photoDIBO-OH tracked by time-resolved IR spectroscopy","authors":"L. Denninger, H. Brunst, L. J. G. W. van Wilderen, M. Horz, H. M. A. Masood, C. D. McNitt, I. Burghardt, V. V. Popik, J. Bredenbeck","doi":"10.1063/5.0196923","DOIUrl":"https://doi.org/10.1063/5.0196923","url":null,"abstract":"Click chemistry refers to selective reactions developed for grafting of bio(macro)molecules in their biological media. Caged click compounds have been employed to spatiotemporally control click reactions. Here, we survey the uncaging of photo-dibenzocyclooctyne-OH (photoDIBO-OH) to its click-chemistry active form DIBO-OH, with particular attention to its conversion timescale and efficiency. Ultraviolet pump–infrared probe experiments reveal a stepwise decarbonylation: first, carbon monoxide (C≡O) is released within 1.8 ps, and then, it converts, within 10 ps, to DIBO-OH. Completion of uncaging is achieved with an efficiency of ∼50%. A successful demonstration of two-photon uncaging of photoDIBO-OH at long wavelength (700 nm) confers enhanced in vivo compatibility and proceeds on the same timescale.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140837194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, an energy decomposition analysis (EDA) method with the strategy of density matrix, called DM-EDA, is proposed on the basis of single reference electronic structure calculations. Different from traditional EDA methods, instead of an intermediate state wave function, the EDA terms in DM-EDA are expressed in the forms of the density matrix. This method can be carried out with various kinds of density matrices. With the efficient implementation, DM-EDA not only greatly improves the computational efficiency but also provides quantitative knowledge of intermolecular interactions with a large number of monomers.
{"title":"Energy decomposition analysis method using density matrix formulation","authors":"Yueyang Zhang, Longxiang Yan, Wei Wu, Peifeng Su","doi":"10.1063/5.0202787","DOIUrl":"https://doi.org/10.1063/5.0202787","url":null,"abstract":"In this work, an energy decomposition analysis (EDA) method with the strategy of density matrix, called DM-EDA, is proposed on the basis of single reference electronic structure calculations. Different from traditional EDA methods, instead of an intermediate state wave function, the EDA terms in DM-EDA are expressed in the forms of the density matrix. This method can be carried out with various kinds of density matrices. With the efficient implementation, DM-EDA not only greatly improves the computational efficiency but also provides quantitative knowledge of intermolecular interactions with a large number of monomers.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140837372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Olivia Bennett, Antonia Freibert, K. Eryn Spinlove, Graham A. Worth
Quantum dynamics simulations are becoming a standard tool for simulating photo-excited molecular systems involving a manifold of coupled states, known as non-adiabatic dynamics. While these simulations have had many successes in explaining experiments and giving details of non-adiabatic transitions, the question remains as to their predictive power. In this work, we present a set of quantum dynamics simulations on cyclobutanone using both grid-based multi-configuration time-dependent Hartree and direct dynamics variational multi-configuration Gaussian methods. The former used a parameterized vibronic coupling model Hamiltonian, and the latter generated the potential energy surfaces on the fly. The results give a picture of the non-adiabatic behavior of this molecule and were used to calculate the signal from a gas-phase ultrafast electron diffraction (GUED) experiment. Corresponding experimental results will be obtained and presented at a later stage for comparison to test the predictive power of the methods. The results show that over the first 500 fs after photo-excitation to the S2 state, cyclobutanone relaxes quickly to the S1 state, but only a small population relaxes further to the S0 state. No significant transfer of population to the triplet manifold is found. It is predicted that the GUED experiments over this time scale will see signals related mostly to the C–O stretch motion and elongation of the molecular ring along the C–C–O axis.
{"title":"Prediction through quantum dynamics simulations: Photo-excited cyclobutanone","authors":"Olivia Bennett, Antonia Freibert, K. Eryn Spinlove, Graham A. Worth","doi":"10.1063/5.0203654","DOIUrl":"https://doi.org/10.1063/5.0203654","url":null,"abstract":"Quantum dynamics simulations are becoming a standard tool for simulating photo-excited molecular systems involving a manifold of coupled states, known as non-adiabatic dynamics. While these simulations have had many successes in explaining experiments and giving details of non-adiabatic transitions, the question remains as to their predictive power. In this work, we present a set of quantum dynamics simulations on cyclobutanone using both grid-based multi-configuration time-dependent Hartree and direct dynamics variational multi-configuration Gaussian methods. The former used a parameterized vibronic coupling model Hamiltonian, and the latter generated the potential energy surfaces on the fly. The results give a picture of the non-adiabatic behavior of this molecule and were used to calculate the signal from a gas-phase ultrafast electron diffraction (GUED) experiment. Corresponding experimental results will be obtained and presented at a later stage for comparison to test the predictive power of the methods. The results show that over the first 500 fs after photo-excitation to the S2 state, cyclobutanone relaxes quickly to the S1 state, but only a small population relaxes further to the S0 state. No significant transfer of population to the triplet manifold is found. It is predicted that the GUED experiments over this time scale will see signals related mostly to the C–O stretch motion and elongation of the molecular ring along the C–C–O axis.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140837507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In nonequilibrium statistical physics, quantifying the nearest (and higher-order) neighbors and free volumes of particles in many-body systems is crucial to elucidating the origin of macroscopic collective phenomena, such as glass/granular jamming transitions and various aspects of the behavior of active matter. However, conventional techniques (based on a fixed-distance cutoff or the Voronoi construction) have mainly been applied to equilibrated, homogeneous, and monodisperse particle systems. In this paper, we implement simple and efficient methods for local structure analysis in nonequilibrium, inhomogeneous, and polydisperse hard disk systems. We show how these novel methods can overcome the difficulties encountered by conventional techniques as well as demonstrate some applications.
{"title":"Simple and efficient methods for local structural analysis in polydisperse hard disk systems","authors":"Daigo Mugita, Kazuyoshi Souno, Hiroaki Koyama, Taisei Nakamura, Masaharu Isobe","doi":"10.1063/5.0194873","DOIUrl":"https://doi.org/10.1063/5.0194873","url":null,"abstract":"In nonequilibrium statistical physics, quantifying the nearest (and higher-order) neighbors and free volumes of particles in many-body systems is crucial to elucidating the origin of macroscopic collective phenomena, such as glass/granular jamming transitions and various aspects of the behavior of active matter. However, conventional techniques (based on a fixed-distance cutoff or the Voronoi construction) have mainly been applied to equilibrated, homogeneous, and monodisperse particle systems. In this paper, we implement simple and efficient methods for local structure analysis in nonequilibrium, inhomogeneous, and polydisperse hard disk systems. We show how these novel methods can overcome the difficulties encountered by conventional techniques as well as demonstrate some applications.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140837264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jorge Nochebuena, Andrew C. Simmonett, G. Andrés Cisneros
Hybrid quantum mechanics/molecular mechanics (QM/MM) simulations have become an essential tool in computational chemistry, particularly for analyzing complex biological and condensed phase systems. Building on this foundation, our work presents a novel implementation of the Gaussian Electrostatic Model (GEM), a polarizable density-based force field, within the QM/MM framework. This advancement provides seamless integration, enabling efficient and optimized QM/GEM calculations in a single step using the LICHEM Code. We have successfully applied our implementation to water dimers and hexamers, demonstrating the ability to handle water systems with varying numbers of water molecules. Moreover, we have extended the application to describe the double proton transfer of the aspartic acid dimer in a box of water, which highlights the method’s proficiency in investigating heterogeneous systems. Our implementation offers the flexibility to perform on-the-fly density fitting or to utilize pre-fitted coefficients to estimate exchange and Coulomb contributions. This flexibility enhances efficiency and accuracy in modeling molecular interactions, especially in systems where polarization effects are significant.
{"title":"Seamless integration of GEM, a density based-force field, for QM/MM simulations via LICHEM, Psi4, and Tinker-HP","authors":"Jorge Nochebuena, Andrew C. Simmonett, G. Andrés Cisneros","doi":"10.1063/5.0200722","DOIUrl":"https://doi.org/10.1063/5.0200722","url":null,"abstract":"Hybrid quantum mechanics/molecular mechanics (QM/MM) simulations have become an essential tool in computational chemistry, particularly for analyzing complex biological and condensed phase systems. Building on this foundation, our work presents a novel implementation of the Gaussian Electrostatic Model (GEM), a polarizable density-based force field, within the QM/MM framework. This advancement provides seamless integration, enabling efficient and optimized QM/GEM calculations in a single step using the LICHEM Code. We have successfully applied our implementation to water dimers and hexamers, demonstrating the ability to handle water systems with varying numbers of water molecules. Moreover, we have extended the application to describe the double proton transfer of the aspartic acid dimer in a box of water, which highlights the method’s proficiency in investigating heterogeneous systems. Our implementation offers the flexibility to perform on-the-fly density fitting or to utilize pre-fitted coefficients to estimate exchange and Coulomb contributions. This flexibility enhances efficiency and accuracy in modeling molecular interactions, especially in systems where polarization effects are significant.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140837200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arghyadeep Basu, Nathan Rafisiman, Saar Shaek, Rachel Lifer, Vivek Yadav, Yaron Kauffmann, Yehonadav Bekenstein, Lev Chuntonov
Functionalization of perovskite nanocrystal surfaces with thiocyanate anions presents a transformative approach to enhancing stability and photoluminescence quantum yield (PLQY) through surface defect passivation. This study investigates the role of thiocyanate ligands in modifying the optoelectronic properties of CsPbBr3 nanocrystals. We employed ultrafast two-dimensional infrared spectroscopy to investigate the nature of the dynamic interaction of thiocyanate ligands with nanocrystal surfaces, providing insights into the mechanisms underlying the observed increase in PLQY and stability. Our analysis reveals that the thiocyanate ligands efficiently passivate the surface defects, thereby enhancing the PLQY and the stability of the treated nanocrystals. The spectroscopic evidence supports a model where thiocyanate binds to under-coordinated lead atoms, contributing to a stable nanocrystal surface with enhanced optoelectronic performance. This ligand-induced passivation mechanism advances our understanding of surface chemistry's role in optimizing nanomaterials for solar cell and LED applications.
用硫氰酸根阴离子对包晶石纳米晶体表面进行功能化处理，是通过表面缺陷钝化提高稳定性和光致发光量子产率（PLQY）的一种变革性方法。本研究探讨了硫氰酸配体在改变 CsPbBr3 纳米晶体光电特性中的作用。我们采用超快二维红外光谱来研究硫氰酸配体与纳米晶体表面动态相互作用的性质，从而深入了解观察到的 PLQY 和稳定性增加的内在机制。我们的分析表明，硫氰酸配体有效地钝化了表面缺陷，从而提高了经处理的纳米晶体的 PLQY 和稳定性。光谱证据支持这样一种模型：硫氰酸盐与配位不足的铅原子结合，有助于形成稳定的纳米晶体表面，从而提高光电性能。这种配体诱导的钝化机制加深了我们对表面化学在优化太阳能电池和 LED 应用纳米材料中的作用的理解。
{"title":"Insights into thiocyanate-enhanced photoluminescence in CsPbBr3 nanocrystals by ultrafast two-dimensional infrared spectroscopy","authors":"Arghyadeep Basu, Nathan Rafisiman, Saar Shaek, Rachel Lifer, Vivek Yadav, Yaron Kauffmann, Yehonadav Bekenstein, Lev Chuntonov","doi":"10.1063/5.0200873","DOIUrl":"https://doi.org/10.1063/5.0200873","url":null,"abstract":"Functionalization of perovskite nanocrystal surfaces with thiocyanate anions presents a transformative approach to enhancing stability and photoluminescence quantum yield (PLQY) through surface defect passivation. This study investigates the role of thiocyanate ligands in modifying the optoelectronic properties of CsPbBr3 nanocrystals. We employed ultrafast two-dimensional infrared spectroscopy to investigate the nature of the dynamic interaction of thiocyanate ligands with nanocrystal surfaces, providing insights into the mechanisms underlying the observed increase in PLQY and stability. Our analysis reveals that the thiocyanate ligands efficiently passivate the surface defects, thereby enhancing the PLQY and the stability of the treated nanocrystals. The spectroscopic evidence supports a model where thiocyanate binds to under-coordinated lead atoms, contributing to a stable nanocrystal surface with enhanced optoelectronic performance. This ligand-induced passivation mechanism advances our understanding of surface chemistry's role in optimizing nanomaterials for solar cell and LED applications.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140827654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Murugesan Panneerselvam, Reshma Rensil Francis, Singaravel Nathiya, Rajadurai Vijay Solomon, Madhavan Jaccob, Luciano T. Costa
Understanding excited-state intramolecular proton transfer (ESIPT) is essential for designing organic molecules to enhance photophysical and luminophore properties in the development of optoelectronic devices. In this context, an attempt has been made to understand the impact of substituents on the ESIPT process of 2-(oxazolinyl)-phenol. Electron donating (EDG: –NH2, –OCH3, and –CH3) and electron withdrawing (EWG: –Cl, –Br, –COOH, –CF3, –CN, and –NO2) substitutions have been computationally designed and screened through density functional theory (DFT) and time-dependent density-functional theory (TDDFT) calculations. Furthermore, the ground state intramolecular proton transfer and ESIPT mechanisms of these designed luminophores are explored using the transition state theory. The results reveal that molecules with EDG show higher absorption and emission peaks than molecules with EWG and also indicate that the mobility of charge carriers in 2-(oxazolinyl)-phenol derivatives is significantly influenced by substituents. We found that the EWGs decrease the reorganization energy and increase the vertical ionization potential and electron affinity values, as well as the highest occupied molecular orbital-lowest unoccupied molecular orbital gap, compared to the EDG substituted molecules. Significantly, the excited state (S1) of the keto emission (K) form shows notably larger values for the EDG substitutions. The intersystem crossing pathway efficiency weakens with reduced spin–orbit coupling matrix element in the enol form with electron-donating substituents and vice versa in the keto form during S1–T3 transitions. Our research links intramolecular proton transfers and triplet generation, making these substituted molecules appealing for optoelectronic devices. Introducing EDGs, such as –NH2, boosts the ESIPT reaction in 2-(oxazolinyl)-phenol. This study guides designing ESIPT emitters with unique photophysical properties.
{"title":"Exploring electron donor and acceptor effects: DFT analysis of ESIPT/GSIPT in 2-(oxazolinyl)-phenols for photophysical and luminophore enhancement","authors":"Murugesan Panneerselvam, Reshma Rensil Francis, Singaravel Nathiya, Rajadurai Vijay Solomon, Madhavan Jaccob, Luciano T. Costa","doi":"10.1063/5.0202890","DOIUrl":"https://doi.org/10.1063/5.0202890","url":null,"abstract":"Understanding excited-state intramolecular proton transfer (ESIPT) is essential for designing organic molecules to enhance photophysical and luminophore properties in the development of optoelectronic devices. In this context, an attempt has been made to understand the impact of substituents on the ESIPT process of 2-(oxazolinyl)-phenol. Electron donating (EDG: –NH2, –OCH3, and –CH3) and electron withdrawing (EWG: –Cl, –Br, –COOH, –CF3, –CN, and –NO2) substitutions have been computationally designed and screened through density functional theory (DFT) and time-dependent density-functional theory (TDDFT) calculations. Furthermore, the ground state intramolecular proton transfer and ESIPT mechanisms of these designed luminophores are explored using the transition state theory. The results reveal that molecules with EDG show higher absorption and emission peaks than molecules with EWG and also indicate that the mobility of charge carriers in 2-(oxazolinyl)-phenol derivatives is significantly influenced by substituents. We found that the EWGs decrease the reorganization energy and increase the vertical ionization potential and electron affinity values, as well as the highest occupied molecular orbital-lowest unoccupied molecular orbital gap, compared to the EDG substituted molecules. Significantly, the excited state (S1) of the keto emission (K) form shows notably larger values for the EDG substitutions. The intersystem crossing pathway efficiency weakens with reduced spin–orbit coupling matrix element in the enol form with electron-donating substituents and vice versa in the keto form during S1–T3 transitions. Our research links intramolecular proton transfers and triplet generation, making these substituted molecules appealing for optoelectronic devices. Introducing EDGs, such as –NH2, boosts the ESIPT reaction in 2-(oxazolinyl)-phenol. This study guides designing ESIPT emitters with unique photophysical properties.","PeriodicalId":501648,"journal":{"name":"The Journal of Chemical Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140827558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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