Crystal structure evaluation: calculating relative stabilities and other criteria: general discussion

Addicoat, Matthew A.; Adjiman, Claire S.; Arhangelskis, Mihails; Beran, Gregory J. O.; Bowskill, David H.; Brandenburg, Jan Gerit; Braun, Doris E.; Burger, Virginia M.; Cole, Jason C.; Cruz‐Cabeza, Aurora J.; Day, Graeme M.; Deringer, Volker L.; Guo, Rui; Hare, Alan; Helfferich, Julian; Hoja, Johannes; Iuzzolino, Luca; Jobbins, Samuel Alexander; Marom, Noa; McKay, David; Mitchell, John B. O.; Mohamed, Sharmarke; Neumann, Marcus A.; Lill, Sten Nilsson; Nyman, Jonas; Oganov, Artem R.; Piaggi, Pablo M.; Price, Sarah L.; Reutzel‐Edens, Susan M.; Rietveld, Ivo B.; Ruggiero, Michael T.; Ryder, Matthew R.; Sastre, Germán; Schön, J. Christian; Taylor, Christopher K.; Tkatchenko, Alexandre; Tsuzuki, Seiji; Ende, Joost van den; Woodley, Scott M.; Woollam, Grahame R.; Zhu, Qiang

doi:10.1039/c8fd90031k

Cited by 9 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…That study also found that further refining the crystal structures with higher-level wave function models frequently decreased the molar volumes relative to the B86bPBE-XDM calculations, bringing them into closer agreement with the experiment. However, such wave function-based calculations are somewhat more computationally expensive, so they are not pursued here.…”

Section: Results and Discussionmentioning

confidence: 99%

Improving Predicted Nuclear Magnetic Resonance Chemical Shifts Using the Quasi-Harmonic Approximation

McKinley

Beran

2019

J. Chem. Theory Comput.

Self Cite

View full text Add to dashboard Cite

Ab initio nuclear magnetic resonance chemical shift prediction plays an important role in the determination or validation of crystal structures. The ability to predict chemical shifts more accurately can translate to increased confidence in the resulting chemical shift or structural assignments. Standard electronic structure predictions for molecular crystal structures neglect thermal expansion, which can lead to an appreciable underestimation of the molar volumes. This study examines this volume error and its impact on 68 13C- and 28 15N-predicted chemical shifts taken from 20 molecular crystals. It assesses the ability to recover more realistic room-temperature crystal structures using the quasi-harmonic approximation and how refining the structures impacts the chemical shifts. Several pharmaceutical molecular crystals are also examined in more detail. On the whole, accounting for quasi-harmonic expansion changes the 13C and 15N chemical shifts by 0.5 and 1.0 ppm on average. This, in turn, reduces the root-mean-square errors relative to experiment by 0.3 ppm for 13C and 0.7 ppm for 15N. Although the statistical impacts are modest, changes in individual chemical shifts can reach multiple ppm. Accounting for thermal expansion in molecular crystal chemical shift prediction may not be needed routinely, but the systematic trend toward improved accuracy with the experiment could be useful in cases where discrimination between structural candidates is challenging, as in the pharmaceutical theophylline.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Improving Predicted Nuclear Magnetic Resonance Chemical Shifts Using the Quasi-Harmonic Approximation

McKinley

Beran

2019

J. Chem. Theory Comput.

Self Cite

View full text Add to dashboard Cite

show abstract

“…2 There is an ongoing effort to develop theoretical methods that would reliably describe such minute differences. [3][4][5][6] When the binding energy of a solid or a molecular cluster is decomposed using many-body expansion, the twobody contribution, corresponding to the binding of dimers, is the largest and as such it receives most of the attention in method development. However, nonadditive higher-order contributions, such as three-body and four-body terms can be important as well.…”

Section: Introductionmentioning

confidence: 99%

“…Such molecular solids often have different phases or polymorphs that differ very little in energy. , For example, in more than half of the polymorph pairs studied by Nyman and Day, the lattice energy difference was found to be less than 0.5 kcal/mol . There is an ongoing effort to develop theoretical methods that would reliably describe such minute differences. − When the binding energy of a solid or a molecular cluster is decomposed using many-body expansion, the two-body contribution, corresponding to the binding of dimers, is the largest and as such it receives most of the attention in method development. However, nonadditive higher-order contributions, such as three-body and four-body terms can be important as well.…”

Section: Introductionmentioning

confidence: 99%

Random Phase Approximation Applied to Many-Body Noncovalent Systems

Modrzejewski

Yourdkhani

Klimeš

2019

J. Chem. Theory Comput.

View full text Add to dashboard Cite

The random phase approximation (RPA) has received a considerable interest in the field of modeling systems where noncovalent interactions are important. Its advantages over widely used density functional theory (DFT) approximations are the exact treatment of exchange and the description of long-range correlation. In this work we address two open questions related to RPA. First, how accurately RPA describes nonadditive interactions encountered in many-body expansion of a binding energy. We consider three-body nonadditive energies in molecular and atomic clusters. Second, how does the accuracy of RPA depend on input provided by different DFT models, without resorting to selfconsistent RPA procedure which is currently impractical for calculations employing periodic boundary conditions. We find that RPA based on the SCAN0 and PBE0 models, i.e., hybrid DFT, achieves an overall accuracy between CCSD and MP3 on a dataset of molecular trimers of Řezáč et al. (J. Chem. Theory. Comput. 2015, 11, 3065) Finally, many-body expansion for molecular clusters and solids often leads to a large number of small contributions that need to be calculated with a high precision. We therefore present a cubic-scaling (or SCF-like) implementation of RPA in atomic basis set, which is designed for calculations with a high numerical precision. rors originating from the exchange functional are on the same order as the errors originating from the missing dispersion energy. [19][20][21] Approximate exchange functionals alone can lead to both strongly overestimated and underestimated noncovalent interactions. 22 For two body systems such issues tend to be masked by adjusting the equilibrium-and short-distance behavior of the dispersion correction. 19 However, the three-body exchange errors cannot be compensated in a similar way by adjusting the pairwise additive dispersion corrections. 19 Overall, the conclusion originating from the existing literature is that no existing semilocal functional can reliably account for many body effects. 21,23 Affordable schemes based on perturbation theory could offer higher and systematically improvable accuracy for calculations of condensed systems compared to standard DFT functionals. 21,[24][25][26][27] Of such schemes, the random phase approximation to the correlation energy (RPA) is promising as it is both compatible with the Hartree-Fock (HF) exchange and it contains terms describing higher-order (nonadditive) correlation effects. 28,29 RPA has been tested for interaction energies of dimers, 30-32 for adsorption, [33][34][35] or for molecular 36-39 and atomic solids 40 and interfaces. 41,42 For the cases involving noncovalent interactions, high accuracy has been achieved with addition of the singles corrections. 43,44 However, its accuracy for predicting nonadditive energies is unknown and this is one of our interests in this work. Moreover, most of the RPA calculations nowadays are performed non-self-consistently, using DFT orbitals and energies in the RPA energy expression. Here we obtain RPA results usi...

show abstract

“…To verify and improve the accuracy of in-silico crystal structure prediction, heat capacities of different polymorphs from 0 K to room temperature are of interest, so that their calculated stability hierarchies and energy contents can be compared with experimental values. [3][4][5][6] Therefore, in this paper, heat capacity data are reported starting at 10 K (with extrapolation to 0 K) for forms I and III. Both forms convert into form II around room temperature followed by melting.…”

Section: Introductionmentioning

confidence: 99%

The Phase Diagram of the API Benzocaine and Its Highly Persistent, Metastable Crystalline Polymorphs

Rietveld¹,

Akiba²,

Barrio³

et al. 2023

Preprint

View full text Add to dashboard Cite

The availability of sufficient amounts of form I of benzocaine has led to the investigation of its phase relationships with the other two existing forms II and III using adiabatic calorimetry, powder X-ray diffraction, and high-pressure differential thermal analysis. The latter two forms were known to have an enantiotropic phase relationship with form III stable at low-temperature and high-pressure, while form II is stable at room temperature. Using adiabatic calorimetry data, it can be concluded, that form I is the stable low-temperature, high-pressure form, which also happens to be stable at room temperature; however, form II, due to its persistence at room temperature, is still the most convenient polymorph to use in formulations. Form III presents a case of overall monotropy and does not possess any stability domain in the pressure-temperature phase diagram. Heat capacity data for benzocaine have been obtained by adiabatic calorimetry from 11 K up to 369 K above its melting point, which can be used to compare to results from in-silico crystal structure prediction.

show abstract

Crystal structure evaluation: calculating relative stabilities and other criteria: general discussion

Cited by 9 publications

References 0 publications

Improving Predicted Nuclear Magnetic Resonance Chemical Shifts Using the Quasi-Harmonic Approximation

Improving Predicted Nuclear Magnetic Resonance Chemical Shifts Using the Quasi-Harmonic Approximation

Random Phase Approximation Applied to Many-Body Noncovalent Systems

The Phase Diagram of the API Benzocaine and Its Highly Persistent, Metastable Crystalline Polymorphs

Contact Info

Product

Resources

About