Hybrid functionals often improve considerably the accuracy of density-functional calculations, in particular of quantities resulting from the band structure. In plane-wave (PW) calculations this benefit comes at the cost of an increase in computation time by several orders of magnitude. For this reason, large-scale problems addressed within the PW formalism have to rely on pre-relaxed atomistic geometries, obtained with cheaper local or semi-local exchange-correlation functionals. We investigate how suitable these geometries are when plugged into single-point hybrid-DFT calculations. Based on several case studies, we find two important sources of error originating from (i) bond strain and (ii) over-mixing between defect and crystalline states. The first arises from the mismatch between the pre-relaxed geometry and that obtained after a subsequent hybrid-DFT-level relaxation. The second occurs when defect states edging an underestimated band gap artificially mix with crystalline states, affecting the local bonding character of the defect, and therefore leading the spurious hybrid-DFT energies. Due to cancelation effects, the lingering strain contributes little ($\lesssim10$ meV) to the error bar of quantities based on energy differences of pre-relaxed structures. The error from state over-mixing does not benefit from cancelation effects and has to be monitored with caution.
An evaluation for geometries, formation enthalpies, and dissociation energies of diatomic and triatomic (C, H, N, O), NO3, and HNO3 molecules from the PAW DFT method with PBE and optB88-vdW functionals
A Comparative Study of Molecular Dynamics Approaches for Simulating Ionic Conductivity in Solid Lithium Electrolytes
Université de Montréal（蒙特利尔大学）；Mila – Quebec AI Institute（米拉-魁北克人工智能研究所）；National Research Council Canada（加拿大国家研究委员会）；Institut Courtois, Université de Montréal（蒙特利尔大学库尔图瓦研究所）
Post density functional theoretical studies of highly polar semiconductive Pb(Ti$_{1-x}$Ni$_{x}$)O$_{3-x}$ solid solutions: The effects of cation arrangement on band gap
Aluminum and Gallium Distribution in the Lu3(Al5-xGax)O12:Ce Multicomponent Garnet Scintillators Investigated by the Solid-State NMR and DFT calculations
用~（27）Al和~（71）Ga MAS NMR结合单晶~（71）Ga NMR研究了混合晶体Lu_3Al_（5-x）Ga_xO_（12）中Al和Ga原子在石榴石结构中四面体和八面体位置上的分布。在实验研究的基础上，采用密度泛函理论进行了理论计算，预测了混合石榴石中Ga取代Al的趋势。实验和理论结果表明，在石榴石结构中的四面体和八面体位置上的Al和Ga的不均匀分布，具有比Al更大的离子半径的Ga强烈偏好占据石榴石结构中具有较小体积的四面体位置。在密度泛函理论的框架下，计算了所有化合物的Al和Ga核的四极耦合常数和化学位移参数，并计算了Al和Ga核的电场梯度.
Comparative Density Functional Theory and Density Functional Tight Binding Study of Arginine and Arginine-Rich Cell-Penetrating Peptide TAT Adsorption on Anatase TiO2
Exploring conformational energy landscape of glassy disaccharides by CPMAS 13C NMR and DFT/GIAO simulations. II. Enhanced molecular flexibility in amorphous trehalose
本文讨论了比较使用化学位移表面来模拟非晶态固体态二糖的实验13 C CPMAS数据，特别注意海藻糖的-1-1键，吡喃糖环之间的-1，4键（乳糖）和暗示呋喃糖环的键（蔗糖）。分子力学与DFT/GIAO从头算方法的结合提供了玻璃中构象分布的可靠结构信息。结果解释为与其他糖相比，海藻糖在非晶态固体状态下具有增强的灵活性。试图将这种性质与玻璃中分子内和分子间氢键网络之间的平衡联系起来。
Uncertainty of DFT calculated mechanical and structural properties of solids due to incompatibility of pseudopotentials and exchange-correlation functionals
DFT based investigation of the structural, magnetic, electronic, and half-metallic properties of solid In$_{1-x}$Ti$_{x}$Sb solutions
为了揭示替代的效果，Ti掺杂的InSb合金，我们完成了第一性原理预测内FPLAPW+lo方法。我们使用GGA-PBESol方案结合改进的TB-mBJ方法预测了In $_{1-x}$ Ti $_{x}$ Sb的结构、电子和磁性，其中$x = 0$、$0.125$、$0.25$、$0.50$、$0.75$、$0.875$和$1$的浓度分别为0.我们的晶格参数被发现与现有的理论和实验数据有利的协议。计算表明，所有结构都是能量稳定的。替代掺杂转换的离子特性的InSb化合物在半金属铁磁comportment浓度$x = 0$，$0.125$，$0.25$，和$0.50$，与自旋极化$100$ %在费米能级，和金属性质的在$_{0.25}$ Ti $_{0.75}$ Sb和在$_{0.125}$ Ti $_{0.875}$ Sb。总磁矩也估计约为1 $μ_{\text{B}}$。In $_{0.875}$ Ti $_{0.125}$ Sb、In $_{0.75}$ Ti $_{0.25}$ Sb和In $_{0.50}$ Ti $_{0.50}$ Sb具有半金属铁磁体性能，它们可以作为自旋电子学应用的未来申请者。
Force correcting atom centered potentials for generalized gradient approximated density functional theory: Approaching hybrid functional accuracy for geometries and harmonic frequencies in small chlorofluorocarbons
Deformation, lattice instability, and metallization during solid-solid structural transformations under general applied stress tensor: example of Si I -> Si II
采用密度泛函理论（DFT）研究了半导体Si I（立方A4结构）和金属Si II（四方A5结构）在一般应力张量作用下的固-固相变（PT）过程中的应力-应变行为、弹性不稳定性和金属化.与正常的应力（$σ_1$，$σ_2$，$σ_3$）作用沿$\left<110 \right>$，$\left<1\bar{1}0 \right>$，和$\left<001\right>$，分别指示模拟单元，我们确定了6个独立的应力，驱动硅I $\rightarrow$硅II PT的晶格不稳定性的组合，和一个超导金属电子过渡。金属化先于结构PT，因此，应力Si I可以是金属。令人惊讶的是，无应力的Si II在DFT中是亚稳态的。值得注意的是，静水压力的PT为75.81 GPa，而在单轴应力下为11.03 GPa（或3.68 GPa平均压力）。我们的主要成果：Si I -> Si II PT由修正相变功的临界值描述，如用相场方法发现的，并且PT准则对于一般施加应力只有两个参数。更一般地说，我们的研究结果是至关重要的揭示新的（和更经济的）材料合成路线的新的或已知的高压阶段下控制和可预测的非流体静力学加载和塑性形变。
Ab-initio chemical potentials of solid and liquid solutions and the chemistry of the Earth's core
基于密度泛函理论，提出了一套用{ \em ab initio}方法计算固液混合物化学势的通用方法。该方法的目的是给一个{ \em ab initio}的方法来处理共存的固体和液体溶液之间的化学平衡，特别是分配比的溶质之间的解决方案。对于液相，该方法是基于热力学积分的一般技术，应用于计算与溶剂和溶质原子的连续相互转化相关的自由能的变化，所需的热平均值由DFT分子动力学模拟计算。对于固相，自由能，因此化学势得到使用DFT计算的振动频率的系统包含取代溶质原子，与非谐波的贡献计算，在需要的地方，通过热力学积分。的实际使用的方法说明，应用它们来研究地球的核心，模拟为解决方案的S，Si和O的Fe的外部液体和内部固体部分之间的化学平衡。计算对核心的化学成分有很强的约束，并允许估计内核/外核边界的温度。
Conditional probability density functional theory for solids
Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem（希伯来大学化学学院分子动力学弗里茨哈伯中心）；Center for Quantum Matter, School of Physics, Zhejiang University（浙江大学物理学院量子物质研究中心）；Departments of Physics and Astronomy and of Chemistry, University of California, Irvine（加州大学尔湾分校物理天文与化学系）；Quantum Dynamics Laboratory, Tsientang Institute of Advanced Study（杭州紫江高等研究院量子动力学实验室）
Frequency-dependent dielectric function of semiconductors with application to physisorption
The dielectric function is one of the most important quantities that describes the electrical and optical properties of solids. Accurate modeling of the frequency-dependent dielectric function has great significance in the study of the long-range van der Waals (vdW) interaction for solids and adsorption. In this work, we calculate the frequency-dependent dielectric functions of semiconductors and insulators using the $GW$ method with and without exciton effects, as well as efficient semilocal density functional theory (DFT), and compare these calculations with a model frequency-dependent diele…
