An effective partial charge model for bulk and surface properties of cubic ZrO2, Y2O3 and yttrium-stabilised zirconia

2019 ◽  
Vol 21 (46) ◽  
pp. 25635-25648
Author(s):  
Thomas S. Hofer ◽  
Franziska M. Kilchert ◽  
Bagas A. Tanjung
Keyword(s):  
Surface Properties ◽  
Partial Charge ◽  
Interaction Potentials ◽  
Charge Model ◽  
Partial Charges ◽  
Partial Charge Model

Novel interaction potentials using effective partial charges are derived, leading to a superior description of bulk and surface properties.

Electronegativity-Based Computation of 29Si Chemical Shifts

1992 ◽  
Vol 271 ◽  
Author(s):  
Henry. M ◽  
Gerardin. C ◽  
Taulelle. F
Keyword(s):  
Chemical Shifts ◽  
Sol Gel ◽  
Partial Charge ◽  
Detailed Structure ◽  
Mean Excitation Energy ◽  
Charge Model ◽  
Partial Charges ◽  
Nuclear Shielding ◽  
Partial Charge Model ◽  
The Mean

ABSTRACTThe Partial Charge Model has been modified to take into account the detailed structure of any molecular sol-gel precursors or inorganic solid networks. Starting from these structure-dependent partial charges, the classical theory of nuclear shielding is applied to compute the electronic cloud compacity <r-3>p, the population unbalance Pu and also the mean excitation energy ΔE. With these three parameters it is possible to explain the chemical shifts variations, spanning from +40 down to -140 ppm, of more than 50 precursors. Depending on the ligands, the well-known upside-down U-curves for series SiXnY4-n (n=0‥4) can be ascribed either to the population unbalance term Pu or to a competition between the two other terms <r-3>p and ΔE.

Alchemical Hydration Free Energy Calculations Using Molecular Dynamics with Explicit Polarization and Induced Polarity Decoupling: An On-the-Fly Approach

2020 ◽  
Author(s):  
Braden Kelly ◽  
William Smith
Keyword(s):  
Free Energy ◽  
Gas Phase ◽  
Free Energy Calculations ◽  
Partial Charge ◽  
Average Absolute Deviation ◽  
Absolute Deviation ◽  
Energy Calculations ◽  
Lennard Jones ◽  
Partial Charges ◽  
The Cost

<div>We present a methodology using fixed charge force-fields for alchemical solvation free energy calculations which accounts for the change in polarity that the solute experiences as it transfers from the gas-phase to the condensed phase. We update partial charges using QM/MM snapshots, decoupling the electric field appropriately when updating the partial charges. We also show how to account for the cost of self-polarization. We test our methodology on 30 molecules ranging from small polar to large drug-like molecules. We use Minimum Basis Iterative Stockholder (MBIS), Restrained Electrostatic Potential (RESP) and AM1-BCC partial charge methodologies. Using our method with MP2/cc-pVTZ and MBIS partial charges yields an Average Absolute Deviation (AAD) of 6.3 kJ·mol−1 in comparison with the AM1-BCC result of 8.6 kJ·mol−1. AM1-BCC is within experimental uncertainty on 10% of the data compared to 30% with our method. We conjecture that results can be further improved by using Lennard-Jones and torsional parameters refitted to MBIS and RESP partial charge methods that use high levels of theory.</div>

Robust molecular representations for modelling and design derived from atomic partial charges

2016 ◽  
Vol 52 (4) ◽  
pp. 681-684 ◽  
Author(s):  
A. R. Finkelmann ◽  
A. H. Göller ◽  
G. Schneider
Keyword(s):  
Ab Initio ◽  
Molecular Modelling ◽  
Partial Charge ◽  
Partial Charges

Ab initio partial charge schemes are identified for molecular modelling purposes, and potential pitfalls of their application are discussed.

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