Fast Treatment of Noncovalent Packing Using Dispersion-Corrected Harris Approximate Density Functional Theory

2017 ◽  
Author(s):  
Andrey B. Sharapov ◽  
Geoffrey Hutchison

<div> <div> <div> <p>The formation of molecular aggregates and assemblies is an important process across chemistry, biology, and materials science. In applications such as crystal structure prediction, a balance between high accuracy and computational speed is highly desirable. We present a new method for predicting approximate bimolecular potential curves using dispersion-corrected Harris approximate-density functional theory and an improved estimate of the bimolecular electron density. Our results on benzene dimer and thiophene dimer yield potential energy curves within a few percent of MP2 theory and a speedup of ~10x over conventional density functional methods. The code is highly parallel and gives greater speedups on larger systems and basis sets. </p> </div> </div> </div>

2017 ◽  
Author(s):  
Andrey B. Sharapov ◽  
Geoffrey Hutchison

<div> <div> <div> <p>The formation of molecular aggregates and assemblies is an important process across chemistry, biology, and materials science. In applications such as crystal structure prediction, a balance between high accuracy and computational speed is highly desirable. We present a new method for predicting approximate bimolecular potential curves using dispersion-corrected Harris approximate-density functional theory and an improved estimate of the bimolecular electron density. Our results on benzene dimer and thiophene dimer yield potential energy curves within a few percent of MP2 theory and a speedup of ~10x over conventional density functional methods. The code is highly parallel and gives greater speedups on larger systems and basis sets. </p> </div> </div> </div>


Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 40
Author(s):  
Pralok K. Samanta ◽  
Christian J. Burnham ◽  
Niall J. English

In this work, we consider low-enthalpy polymorphs of ice, predicted previously using a modified basin-hopping algorithm for crystal-structure prediction with the TIP4P empirical potential at three pressures (0, 4 and 8 kbar). We compare and (re)-rank the reported ice polymorphs in order of energetic stability, using high-level quantum-chemical calculations, primarily in the guise of sophisticated Density-Functional Theory (DFT) approaches. In the absence of applied pressure, ice Ih is predicted to be energetically more stable than ice Ic, and TIP4P-predicted results and ranking compare well with the results obtained from DFT calculations. However, perhaps not unexpectedly, the deviation between TIP4P- and DFT-calculated results increases with applied external pressure.


Author(s):  
Philip J. Hasnip ◽  
Keith Refson ◽  
Matt I. J. Probert ◽  
Jonathan R. Yates ◽  
Stewart J. Clark ◽  
...  

Density functional theory (DFT) has been used in many fields of the physical sciences, but none so successfully as in the solid state. From its origins in condensed matter physics, it has expanded into materials science, high-pressure physics and mineralogy, solid-state chemistry and more, powering entire computational subdisciplines. Modern DFT simulation codes can calculate a vast range of structural, chemical, optical, spectroscopic, elastic, vibrational and thermodynamic phenomena. The ability to predict structure–property relationships has revolutionized experimental fields, such as vibrational and solid-state NMR spectroscopy, where it is the primary method to analyse and interpret experimental spectra. In semiconductor physics, great progress has been made in the electronic structure of bulk and defect states despite the severe challenges presented by the description of excited states. Studies are no longer restricted to known crystallographic structures. DFT is increasingly used as an exploratory tool for materials discovery and computational experiments, culminating in ex nihilo crystal structure prediction, which addresses the long-standing difficult problem of how to predict crystal structure polymorphs from nothing but a specified chemical composition. We present an overview of the capabilities of solid-state DFT simulations in all of these topics, illustrated with recent examples using the CASTEP computer program.


RSC Advances ◽  
2021 ◽  
Vol 11 (53) ◽  
pp. 33781-33787
Author(s):  
Nursultan E. Sagatov ◽  
Aisulu U. Abuova ◽  
Dinara N. Sagatova ◽  
Pavel N. Gavryushkin ◽  
Fatima U. Abuova ◽  
...  

Based on density functional theory and the crystal structure prediction methods, USPEX and AIRSS, stable intermediate compounds in the Ni–X (X = B, C, and N) systems and their structures were determined in the pressure range of 0–400 GPa.


2021 ◽  
Author(s):  
Zabiollah Mahdavifar

In the present work, a modern method of crystal structure prediction, namely USPEX conjugated with density functional theory (DFT) calculations, was used to predict the new stable structures of BnPn (n = 12, 24) clusters.


2020 ◽  
Vol 11 (8) ◽  
pp. 2200-2214 ◽  
Author(s):  
Chandler Greenwell ◽  
Jessica L. McKinley ◽  
Peiyu Zhang ◽  
Qun Zeng ◽  
Guangxu Sun ◽  
...  

Widely used crystal structure prediction models based on density functional theory can perform poorly for conformational polymorphs, but a new model corrects those polymorph stability rankings.


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