Modeling the Effects of Solvation on the Structure and Properties of Optical Limiting Materials Using Ab Initio Quantum Chemistry

1997 ◽  
Vol 479 ◽  
Author(s):  
P. N. Day ◽  
Z. Wang ◽  
R. Pachter

Abstracthe Effective Fragment Potential (EFP) model of solvation can now be extended beyond aqueous systems due to the development of transferable exchange repulsion potentials. EFPs for methanol and chloroform have been developed, and calculations with these new EFPs agree well with full ab initio calculations. Ab initio calculations have been carried out on zinc tetraphenyl-octobromyl-porphyrin both with and without the EFP solvation model. While the aqueous calculation, which had its geometry optimized, gave good results, the single-point calculations carried out with the two new solvent models indicate the need for geometry optimization.

1997 ◽  
Vol 488 ◽  
Author(s):  
P.N. Day ◽  
Z. Wang ◽  
R. Pachter

AbstractPorphyrins are a promising class of materials for optical limiting applications, and in the condensed phase solvent effects have been shown to be significant. We report results with a method designed to simulate the effects of discrete solvent molecules, namely the effective fragment potential (EFP) approach which has been implemented for use in ab initio calculations. Further, a simulated annealing (SA) method has been implemented with the EFP solvation model in an attempt to solve the problem of multiple minima in clusters of molecules. The results with this method indicate some success on models of aqueous formamide and aqueous glutamic acid. Ab initio calculations can now be carried out on porphyrins, and the solvation methods are being updated for their use on these systems.


1995 ◽  
Vol 408 ◽  
Author(s):  
Bala Ramalingam ◽  
Michael E. McHenry ◽  
Warren M. Garrison ◽  
James M. MacLaren

AbstractTitanium carbosulfide (Ti2CS) is frequently found as an inclusion phase in Ti - containing steels. It is of considerable interest because, whenever present in preference to the more common manganese sulfide (MnS), it significantly improves the toughness (a very desirable property) of the steel. Currently, to the best of our knowledge, there is no data, either computational or experimental, regarding the structural properties of Ti2CS. This data is needed to understand the influence of the Ti2CS inclusions on the toughness of the host material.In this paper, our results from the ab-initio calculations, using the LKKR-ASA (Layer Korringa Kohn Rostoker method in the Atomic Spheres Approximation) on the equilibrium ground state properties of bulk Ti2CS are presented and discussed. In particular, attention is focused upon (a) the Energy – Atomic Volume curve generated to calculate the equilibrium lattice constant and the bulk modulus, and (b) the density of states calculations. The application of these results to the subsequent study of an interface involving the carbosulfide and the host matrix is also illustrated.


2020 ◽  
Vol 127 (14) ◽  
pp. 145102 ◽  
Author(s):  
Natalia E. Koval ◽  
Joseba Iñaki Juaristi ◽  
Ricardo Díez Muiño ◽  
Maite Alducin

2012 ◽  
Vol 116 (51) ◽  
pp. 26784-26790 ◽  
Author(s):  
Roberto Macovez ◽  
Nuria Lopez ◽  
Marina Mariano ◽  
Marc Maymò ◽  
Jordi Martorell

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