A Systematic Approach to Identify Cooperatively Bound Homotrimers

A systematic multistage computational procedure is presented to investigate cooperativity within trimeric molecular complexes. It is an alternative to exhaustive or stochastic-based approaches. Trimeric clusters were extracted from known crystal structures and optimized in the gas phase, and subsequently filtered using energetic and RMSD structural cutoffs. Three-body interaction energies were computed for the subset of distinct low-energy trimer conformations. The procedure was validated using a set of 20 molecular crystals taken from the Cambridge Structural Database, and 25% of these strucutres gave rise to gas-phase homotrimers that showed a cooperative binding energy at the BP86-D3­(BJ)/def2-SVP//TPSS-D3­(BJ)/def2-TZVP level of theory

JACOB: A Dynamic Database for Computational Chemistry Benchmarking

JACOB (just a collection of benchmarks) is a database that contains four diverse benchmark studies, which in-turn included 72 data sets, with a total of 122 356 individual results. The database is constructed upon a dynamic web framework that allows users to retrieve data from the database via predefined categories. Additional flexibility is made available via user-defined text-based queries. Requested sets of results are then automatically presented as bar graphs, with parameters of the graphs being controllable via the URL. JACOB is currently available at www.wallerlab.org/jacob

Correction to Mapping the Room-Temperature Dynamic Stabilities of Inorganic Halide Double Perovskites

Correction to Mapping the Room-Temperature Dynamic Stabilities of Inorganic Halide Double Perovskite

Mapping the Room-Temperature Dynamic Stabilities of Inorganic Halide Double Perovskites

The diverse chemistry of halide double perovskites (A2MM′X6) has provided material scientists with exciting opportunities to discover new multifunctional materials. However, similar to their single perovskite counterparts, the presence of strongly anharmonic phonons, which can further couple with the electronic subsystem in halide double perovskites, plays a vital role in determining the finite temperature phase stabilities and the lifetime of the photoexcited states in these materials to be used as solar absorbers. Using the high-throughput computational framework that we have previously established for building the database of room-temperature phase stabilities and vibrational anharmonicities for cubic single perovskites, we further extend this database to cover ∼2000 cubic halide double perovskites extracted from the Materials Project database. It is discovered that the halide double perovskites possess higher dynamic stabilities compared to their single perovskite counterparts. The correlation between the vibrational anharmonicity and the complex chemistry of halide double perovskites is uniquely revealed with unsupervised machine learning, highlighting the important role played by the atomic weight of the M and M′ cations and the halide anions. Further examination on the electronic dynamics for 19 selected direct band gap halide double perovskites reveals significantly strengthened electron–phonon coupling behaviors despite their low vibrational anharmonicity. This illustrates a challenge behind the development of halide double perovskites as efficient materials for solar cells but may be harnessed in other applications such as thermochromic sensing

Hybrid Metaheuristic Approach for Nonlocal Optimization of Molecular Systems

Accurate modeling of molecular systems requires a good knowledge of the structure; therefore, conformation searching/optimization is a routine necessity in computational chemistry. Here we present a hybrid metaheuristic optimization (HMO) algorithm, which combines ant colony optimization (ACO) and particle swarm optimization (PSO) for the optimization of molecular systems. The HMO implementation meta-optimizes the parameters of the ACO algorithm on-the-fly by the coupled PSO algorithm. The ACO parameters were optimized on a set of small difluorinated polyenes where the parameters exhibited small variance as the size of the molecule increased. The HMO algorithm was validated by searching for the closed form of around 100 molecular balances. Compared to the gradient-based optimized molecular balance structures, the HMO algorithm was able to find low-energy conformations with a 87% success rate. Finally, the computational effort for generating low-energy conformation(s) for the phenylalanyl-glycyl-glycine tripeptide was approximately 60 CPU hours with the ACO algorithm, in comparison to 4 CPU years required for an exhaustive brute-force calculation

Flexible and Compressible PEDOT:PSS@Melamine Conductive Sponge Prepared via One-Step Dip Coating as Piezoresistive Pressure Sensor for Human Motion Detection

Flexible and wearable pressure sensor may offer convenient, timely, and portable solutions to human motion detection, yet it is a challenge to develop cost-effective materials for pressure sensor with high compressibility and sensitivity. Herein, a cost-efficient and scalable approach is reported to prepare a highly flexible and compressible conductive sponge for piezoresistive pressure sensor. The conductive sponge, poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS)@melamine sponge (MS), is prepared by one-step dip coating the commercial melamine sponge (MS) in an aqueous dispersion of poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS). Due to the interconnected porous structure of MS, the conductive PEDOT:PSS@MS has a high compressibility and a stable piezoresistive response at the compressive strain up to 80%, as well as good reproducibility over 1000 cycles. Thereafter, versatile pressure sensors fabricated using the conductive PEDOT:PSS@MS sponges are attached to the different parts of human body; the capabilities of these devices to detect a variety of human motions including speaking, finger bending, elbow bending, and walking are evaluated. Furthermore, prototype tactile sensory array based on these pressure sensors is demonstrated

Flexible and Compressible PEDOT:PSS@Melamine Conductive Sponge Prepared via One-Step Dip Coating as Piezoresistive Pressure Sensor for Human Motion Detection

Flexible and wearable pressure sensor may offer convenient, timely, and portable solutions to human motion detection, yet it is a challenge to develop cost-effective materials for pressure sensor with high compressibility and sensitivity. Herein, a cost-efficient and scalable approach is reported to prepare a highly flexible and compressible conductive sponge for piezoresistive pressure sensor. The conductive sponge, poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS)@melamine sponge (MS), is prepared by one-step dip coating the commercial melamine sponge (MS) in an aqueous dispersion of poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS). Due to the interconnected porous structure of MS, the conductive PEDOT:PSS@MS has a high compressibility and a stable piezoresistive response at the compressive strain up to 80%, as well as good reproducibility over 1000 cycles. Thereafter, versatile pressure sensors fabricated using the conductive PEDOT:PSS@MS sponges are attached to the different parts of human body; the capabilities of these devices to detect a variety of human motions including speaking, finger bending, elbow bending, and walking are evaluated. Furthermore, prototype tactile sensory array based on these pressure sensors is demonstrated

Flexible and Compressible PEDOT:PSS@Melamine Conductive Sponge Prepared via One-Step Dip Coating as Piezoresistive Pressure Sensor for Human Motion Detection

Flexible and wearable pressure sensor may offer convenient, timely, and portable solutions to human motion detection, yet it is a challenge to develop cost-effective materials for pressure sensor with high compressibility and sensitivity. Herein, a cost-efficient and scalable approach is reported to prepare a highly flexible and compressible conductive sponge for piezoresistive pressure sensor. The conductive sponge, poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS)@melamine sponge (MS), is prepared by one-step dip coating the commercial melamine sponge (MS) in an aqueous dispersion of poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS). Due to the interconnected porous structure of MS, the conductive PEDOT:PSS@MS has a high compressibility and a stable piezoresistive response at the compressive strain up to 80%, as well as good reproducibility over 1000 cycles. Thereafter, versatile pressure sensors fabricated using the conductive PEDOT:PSS@MS sponges are attached to the different parts of human body; the capabilities of these devices to detect a variety of human motions including speaking, finger bending, elbow bending, and walking are evaluated. Furthermore, prototype tactile sensory array based on these pressure sensors is demonstrated

Flexible and Compressible PEDOT:PSS@Melamine Conductive Sponge Prepared via One-Step Dip Coating as Piezoresistive Pressure Sensor for Human Motion Detection

Flexible and wearable pressure sensor may offer convenient, timely, and portable solutions to human motion detection, yet it is a challenge to develop cost-effective materials for pressure sensor with high compressibility and sensitivity. Herein, a cost-efficient and scalable approach is reported to prepare a highly flexible and compressible conductive sponge for piezoresistive pressure sensor. The conductive sponge, poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS)@melamine sponge (MS), is prepared by one-step dip coating the commercial melamine sponge (MS) in an aqueous dispersion of poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS). Due to the interconnected porous structure of MS, the conductive PEDOT:PSS@MS has a high compressibility and a stable piezoresistive response at the compressive strain up to 80%, as well as good reproducibility over 1000 cycles. Thereafter, versatile pressure sensors fabricated using the conductive PEDOT:PSS@MS sponges are attached to the different parts of human body; the capabilities of these devices to detect a variety of human motions including speaking, finger bending, elbow bending, and walking are evaluated. Furthermore, prototype tactile sensory array based on these pressure sensors is demonstrated

Flexible and Compressible PEDOT:PSS@Melamine Conductive Sponge Prepared via One-Step Dip Coating as Piezoresistive Pressure Sensor for Human Motion Detection

Flexible and wearable pressure sensor may offer convenient, timely, and portable solutions to human motion detection, yet it is a challenge to develop cost-effective materials for pressure sensor with high compressibility and sensitivity. Herein, a cost-efficient and scalable approach is reported to prepare a highly flexible and compressible conductive sponge for piezoresistive pressure sensor. The conductive sponge, poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS)@melamine sponge (MS), is prepared by one-step dip coating the commercial melamine sponge (MS) in an aqueous dispersion of poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS). Due to the interconnected porous structure of MS, the conductive PEDOT:PSS@MS has a high compressibility and a stable piezoresistive response at the compressive strain up to 80%, as well as good reproducibility over 1000 cycles. Thereafter, versatile pressure sensors fabricated using the conductive PEDOT:PSS@MS sponges are attached to the different parts of human body; the capabilities of these devices to detect a variety of human motions including speaking, finger bending, elbow bending, and walking are evaluated. Furthermore, prototype tactile sensory array based on these pressure sensors is demonstrated