The Journal of chemical physics最新文献_第7页

Ab initio study of the adsorption properties of CO2 reduction intermediates: The effect of Ni5Ga3 alloy and the Ni5Ga3/ZrO2 interface. Ni5Ga3合金和Ni5Ga3/ZrO2界面对CO2还原中间体吸附性能的影响

The Journal of chemical physics Pub Date : 2022-05-16 DOI: 10.1063/5.0091145

R. A. de Sousa, Vivianne K. Ocampo-Restrepo, L. G. Verga, J. L. D. Da Silva

{"title":"Ab initio study of the adsorption properties of CO2 reduction intermediates: The effect of Ni5Ga3 alloy and the Ni5Ga3/ZrO2 interface.","authors":"R. A. de Sousa, Vivianne K. Ocampo-Restrepo, L. G. Verga, J. L. D. Da Silva","doi":"10.1063/5.0091145","DOIUrl":"https://doi.org/10.1063/5.0091145","url":null,"abstract":"The Ni5Ga3 alloy supported on ZrO2 is a promising catalyst for the reduction of CO2 due to its higher selectivity to methanol at ambient pressure, e.g., activity comparable to industrial catalysts. However, our atomistic understanding of the role of the cooperative effects induced by the Ni5Ga3 alloy formation and its Ni5Ga3/ZrO2 interface in the CO2 reduction is still far from satisfactory. In this work, we tackle these questions by employing density functional theory calculations to investigate the adsorption properties of key CO2 reduction intermediates (CO2, H2, cis-COOH, trans-COOH, HCOO, CO, HCO, and COH) on Ni8, Ga8, Ni5Ga3, (ZrO2)16, and Ni5Ga3/(ZrO2)16. We found that Ni containing clusters tended to assume wetting configurations on the (ZrO2)16 cluster, while the presence of Ga atoms weakens the adsorption energies on the oxide surface. We also observed that CO2 was better activated on the metal-oxide interfaces and on the oxide surface, where it was able to form CO3-like structures. Meanwhile, H2 activation was only observed on Ni sites, which indicates the importance of distinct adsorption sites that can favor different CO2 reduction steps. Moreover, the formation of the metal-oxide interface showed to be beneficial for the adsorption of COOH isomers and unfavorable for the adsorption of HCOO.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132700647","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}

引用次数: 0

Ultrafast vibrational dynamics of the free OD at the air/water interface: Negligible isotopic dilution effect but large isotope substitution effect. 空气/水界面自由OD的超快振动动力学:同位素稀释效应可忽略，但同位素取代效应较大。

The Journal of chemical physics Pub Date : 2022-05-16 DOI: 10.1063/5.0085320

Mohammed Ahmed, S. Nihonyanagi, T. Tahara

{"title":"Ultrafast vibrational dynamics of the free OD at the air/water interface: Negligible isotopic dilution effect but large isotope substitution effect.","authors":"Mohammed Ahmed, S. Nihonyanagi, T. Tahara","doi":"10.1063/5.0085320","DOIUrl":"https://doi.org/10.1063/5.0085320","url":null,"abstract":"Vibrational relaxation dynamics of the OH stretch of water at the air/water interface has been a subject of intensive research, facilitated by recent developments in ultrafast interface-selective nonlinear spectroscopy. However, a reliable determination of the vibrational relaxation dynamics in the OD stretch region at the air/D2O interface has not been yet achieved. Here, we report a study of the vibrational relaxation of the free OD carried out by time-resolved heterodyne-detected vibrational sum frequency generation spectroscopy. The results obtained with the aid of singular value decomposition analysis indicate that the vibrational relaxation (T1) time of the free OD at the air/D2O interface and air/isotopically diluted water (HOD-H2O) interfaces show no detectable isotopic dilution effect within the experimental error, as in the case of the free OH in the OH stretch region. Thus, it is concluded that the relaxation of the excited free OH/OD predominantly proceeds with their reorientation, negating a major contribution of the intramolecular energy transfer. It is also shown that the T1 time of the free OD is substantially longer than that of the free OH, further supporting the reorientation relaxation mechanism. The large difference in the T1 time between the free OD and the free OH (factor of ∼2) may indicate the nuclear quantum effect on the diffusive reorientation of the free OD/OH because this difference is significantly larger than the value expected for a classical rotational motion.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123399821","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}

引用次数: 4

Rotational state specific dissociation dynamics of D2O via the C̃(010) state: The effect of bending vibrational excitation. D2O通过C /(010)态的旋转态比解离动力学:弯曲振动激发的影响。

The Journal of chemical physics Pub Date : 2022-05-16 DOI: 10.1063/5.0091762

Yucheng Wu, Zhao-Han Zhang, Su-e Zhang, Zijie Luo, Yarui Zhao, Shuaikang Yang, Zhenxing Li, Yao Chang, Zhichao Chen, Shengrui Yu, Xueming Yang, Kaijun Yuan

{"title":"Rotational state specific dissociation dynamics of D2O via the C̃(010) state: The effect of bending vibrational excitation.","authors":"Yucheng Wu, Zhao-Han Zhang, Su-e Zhang, Zijie Luo, Yarui Zhao, Shuaikang Yang, Zhenxing Li, Yao Chang, Zhichao Chen, Shengrui Yu, Xueming Yang, Kaijun Yuan","doi":"10.1063/5.0091762","DOIUrl":"https://doi.org/10.1063/5.0091762","url":null,"abstract":"The rotational state resolved photodissociation dynamics of D2O via the C̃(010) state has been investigated by using the D-atom Rydberg tagging time-of-flight technique combined with a tunable vacuum ultraviolet light source. The D-atom action spectrum of the C̃(010) ← X̃(000) band and the corresponding time-of-flight (TOF) spectra of D-atom photoproducts formed following the excitation of D2O to individual rotational transition have been measured. By comparison with the action spectrum of the C̃(000) ← X̃(000) band, the bending vibrational constant of the C̃ state for D2O can be determined to be v2 = 1041.37 ± 0.71 cm-1. From the TOF spectra, the product kinetic energy spectra, the vibrational state distributions of OD products, and the state resolved anisotropy parameters have been determined. The experimental results indicate a dramatic variation in the OD product state distributions for different rotational excitations. This illuminates that there are two distinctive coupling channels from the C̃(010) state to the low-lying electronic states: the homogeneous electronic coupling to the Ã1B1 state, resulting in vibrationally hot OD(X) products, and the Coriolis-type coupling to the B̃1A1 state, producing vibrationally cold but rotationally hot OD(X) and OD(A) products. Furthermore, the three-body dissociation channel is confirmed, which is attributed to the C̃ → 1A2 or C̃ → Ã pathway. In comparison with the previous results of D2O photolysis via the C̃(000) state, it is found that the v2 vibration of the parent molecule enhances both the vibrational and rotational excitations of OD products.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130469711","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}

引用次数: 1

Structural origin of excitations in a colloidal glass-former. 胶体玻璃成形机中激发的结构起源。

The Journal of chemical physics Pub Date : 2022-05-16 DOI: 10.1063/5.0088500

Divya Ganapathi, A. Sood, R. Ganapathy

{"title":"Structural origin of excitations in a colloidal glass-former.","authors":"Divya Ganapathi, A. Sood, R. Ganapathy","doi":"10.1063/5.0088500","DOIUrl":"https://doi.org/10.1063/5.0088500","url":null,"abstract":"Despite decades of intense research, whether the transformation of supercooled liquids into glass is a kinetic phenomenon or a thermodynamic phase transition remains unknown. Here, we analyzed optical microscopy experiments on 2D binary colloidal glass-forming liquids and investigated the structural links of a prominent kinetic theory of glass transition. We examined a possible structural origin for localized excitations, which are building blocks of the dynamical facilitation theory-a purely kinetic approach for the glass transition. To accomplish this, we utilize machine learning methods to identify a structural order parameter termed \"softness\" that has been found to be correlated with reorganization events in supercooled liquids. Both excitations and softness qualitatively capture the dynamical slowdown on approaching the glass transition and motivated us to explore spatial and temporal correlations between them. Our results show that excitations predominantly occur in regions with high softness and the appearance of these high softness regions precedes excitations, thus suggesting a causal connection between them. Thus, unifying dynamical and thermodynamical theories into a single structure-based framework may provide a route to understand the glass transition.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131454867","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}

引用次数: 2

Flexible machine-learning interatomic potential for simulating structural disordering behavior of Li7La3Zr2O12 solid electrolytes. 模拟Li7La3Zr2O12固体电解质结构无序行为的柔性机器学习原子间势。

The Journal of chemical physics Pub Date : 2022-05-16 DOI: 10.1063/5.0090341

Kwangnam Kim, A. Dive, Andrew Grieder, N. Adelstein, Shinyoung Kang, L. Wan, B. Wood

{"title":"Flexible machine-learning interatomic potential for simulating structural disordering behavior of Li7La3Zr2O12 solid electrolytes.","authors":"Kwangnam Kim, A. Dive, Andrew Grieder, N. Adelstein, Shinyoung Kang, L. Wan, B. Wood","doi":"10.1063/5.0090341","DOIUrl":"https://doi.org/10.1063/5.0090341","url":null,"abstract":"Batteries based on solid-state electrolytes, including Li7La3Zr2O12 (LLZO), promise improved safety and increased energy density; however, atomic disorder at grain boundaries and phase boundaries can severely deteriorate their performance. Machine-learning (ML) interatomic potentials offer a uniquely compelling solution for simulating chemical processes, rare events, and phase transitions associated with these complex interfaces by mixing high scalability with quantum-level accuracy, provided that they can be trained to properly address atomic disorder. To this end, we report the construction and validation of an ML potential that is specifically designed to simulate crystalline, disordered, and amorphous LLZO systems across a wide range of conditions. The ML model is based on a neural network algorithm and is trained using ab initio data. Performance tests prove that the developed ML potential can predict accurate structural and vibrational characteristics, elastic properties, and Li diffusivity of LLZO comparable to ab initio simulations. As a demonstration of its applicability to larger systems, we show that the potential can correctly capture grain boundary effects on diffusivity, as well as the thermal transition behavior of LLZO. These examples show that the ML potential enables simulations of transitions between well-defined and disordered structures with quantum-level accuracy at speeds thousands of times faster than ab initio methods.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125032203","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}

引用次数: 7

Difficulty of the evaluation of the barrier height of an open-shell transition state between closed shell minima: The case of small C4n rings. 闭壳极小值间开壳过渡态势垒高度的评定困难:以小C4n环为例。

The Journal of chemical physics Pub Date : 2022-05-16 DOI: 10.1063/5.0090129

G. David, N. Ben Amor, Tao Zeng, N. Suaud, G. Trinquier, J. Malrieu

{"title":"Difficulty of the evaluation of the barrier height of an open-shell transition state between closed shell minima: The case of small C4n rings.","authors":"G. David, N. Ben Amor, Tao Zeng, N. Suaud, G. Trinquier, J. Malrieu","doi":"10.1063/5.0090129","DOIUrl":"https://doi.org/10.1063/5.0090129","url":null,"abstract":"C4n cyclacenes exhibit strong bond-alternation in their equilibrium geometry. In the two equivalent geometries, the system keeps an essentially closed-shell character. The two energy minima are separated by a transition state suppressing the bond-alternation, where the wave function is strongly diradical. This paper discusses the physical factors involved in this energy difference and possible evaluations of the barrier height. The barrier given as the energy difference between the restricted density functional theory (DFT)/B3LYP for the equilibrium and the broken symmetry DFT/B3LYP of the transition state is either negative or small, in contradiction with the most reliable Wave Function Theory calculations. The minimal (two electrons in two molecular orbitals) Complete Active Space self-consistent field (CASSCF) overestimates the barrier, and the subsequent second-order perturbation cancels it. Due to the collective character of the spin-polarization effect, it is necessary to perform a full π CASSCF + second-order perturbation to reach a reasonable value of the barrier, but this type of treatment cannot be applied to large molecules. DFT procedures treating on an equal foot the closed-shell and open-shell geometries have been explored, such as Mixed-Reference Spin-Flip Time-dependent-DFT and a new spin-decontamination proposal, namely, DFT-dressed configuration interaction, but the results still depend on the density functional. M06-2X without or with spin-decontamination gives the best agreement with the accurate wave function results.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131371039","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}

引用次数: 2

Quantum dynamics of the photoinduced charge separation in a symmetric donor-acceptor-donor triad: The role of vibronic couplings, symmetry and temperature. 对称施主-受主-施主三元体中光致电荷分离的量子动力学:振动耦合、对称性和温度的作用。

The Journal of chemical physics Pub Date : 2022-05-14 DOI: 10.1063/5.0089887

D. Picconi

{"title":"Quantum dynamics of the photoinduced charge separation in a symmetric donor-acceptor-donor triad: The role of vibronic couplings, symmetry and temperature.","authors":"D. Picconi","doi":"10.1063/5.0089887","DOIUrl":"https://doi.org/10.1063/5.0089887","url":null,"abstract":"The photoinduced charge separation in a symmetric donor-acceptor-donor (D-A-D) triad is studied quantum mechanically using a realistic diabatic vibronic coupling model. The model includes a locally excited DA*D state and two charge-transfer states D+A-D and DA-D+ and is constructed according to a procedure generally applicable to semirigid D-A-D structures and based on energies, forces, and force constants obtained by quantum chemical calculations. In this case, the electronic structure is described by time-dependent density functional theory, and the corrected linear response is used in conjunction with the polarizable continuum model to account for state-specific solvent effects. The multimode dynamics following the photoexcitation to the locally excited state are simulated by the hybrid Gaussian-multiconfigurational time-dependent Hartree method, and temperature effects are included using thermo field theory. The dynamics are connected to the transient absorption spectrum obtained in recent experiments, which is simulated and fully assigned from first principles. It is found that the charge separation is mediated by symmetry-breaking vibrations of relatively low frequency, which implies that temperature should be accounted for to obtain reliable estimates of the charge transfer rate.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123370795","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}

引用次数: 3

The factorization ansatz for non-local approximations to the exchange-correlation hole. 交换相关洞的非局部近似的分解分析。

The Journal of chemical physics Pub Date : 2022-05-14 DOI: 10.1063/5.0077287

Étienne Cuierrier, Pierre-Olivier Roy, M. Ernzerhof

{"title":"The factorization ansatz for non-local approximations to the exchange-correlation hole.","authors":"Étienne Cuierrier, Pierre-Olivier Roy, M. Ernzerhof","doi":"10.1063/5.0077287","DOIUrl":"https://doi.org/10.1063/5.0077287","url":null,"abstract":"Among the various types of approximations to the exchange-correlation energy (EXC), the completely non-local approach is one of the lesser explored approximation schemes. It has not yet reached the predictive power of the widely used generalized gradient approximations, meta-generalized gradient approximations, hybrids, etc. In non-local functionals pursued here, the electron density at every point in space is employed to express the exchange-correlation energy per particle ϵXC(r) at a given position r. Here, we use the non-local, spherical-averaged density ρ(r,u)=∫dΩu4πρ(r+u) as a starting point to construct approximate exchange-correlation holes through the factorization ansatz ρXC(r, u) = f(r, u)ρ(r, u). We present upper and lower bounds to the exchange energy per particle ϵX(r) in terms of ρ(r, u). The factor f(r, u) is then designed to satisfy various conditions that represent important exchange and correlation effects. We assess the resulting approximations and find that the complex, oscillatory structure of ρ(r, u) makes the construction of a corresponding f(r, u) very challenging. This conclusion, identifying the main issue of the non-local approximation, is supported by a detailed analysis of the resulting exchange-correlation holes.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126579811","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}

引用次数: 0

A neural network-assisted open boundary molecular dynamics simulation method. 一种神经网络辅助开边界分子动力学模拟方法。

The Journal of chemical physics Pub Date : 2022-05-14 DOI: 10.1063/5.0083198

J. Floyd, J. Lukes

引用次数: 2

Entropic surface segregation from athermal polymer blends: Polymer flexibility vs bulkiness. 非热聚合物共混物的表面熵分离:聚合物的柔韧性与体积。

The Journal of chemical physics Pub Date : 2022-05-14 DOI: 10.1063/5.0087587

M. Matsen

{"title":"Entropic surface segregation from athermal polymer blends: Polymer flexibility vs bulkiness.","authors":"M. Matsen","doi":"10.1063/5.0087587","DOIUrl":"https://doi.org/10.1063/5.0087587","url":null,"abstract":"We examine athermal binary blends composed of conformationally asymmetric polymers of equal molecular volume next to a surface of width ξ. The self-consistent field theory (SCFT) of Gaussian chains predicts that the more compact polymer with the shorter average end-to-end length, R0, is entropically favored at the surface. Here, we extend the SCFT to worm-like chains with small persistence lengths, ℓp, relative to their contour lengths, ℓc, for which R0≈2ℓpℓc. In the limit of ℓp ≪ ξ, we recover the Gaussian-chain prediction where the segregation depends only on the product ℓpℓc, but for realistic polymer/air surfaces with ξ ∼ ℓp, the segregation depends separately on the two quantities. Although the surface continues to favor flexible polymers with smaller ℓp and bulky polymers with shorter ℓc, the effect of bulkiness is more pronounced. This imbalance can, under specific conditions, lead to anomalous surface segregation of the more extended polymer. For this to happen, the polymer must be bulkier and stiffer, with a stiffness that is sufficient to produce a larger R0 yet not so rigid as to reverse the surface affinity that favors bulky polymers.","PeriodicalId":446961,"journal":{"name":"The Journal of chemical physics","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123306109","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}

引用次数: 2