Collage of hardware in the Quantum Cave.

Database and Archive for Molecular and Materials Structure Information

Database and Archive for Molecular and Materials Structure InformationDatabase and Archive for Molecular and Materials Structure Information

Please contact us in the case you have chemical structure information needs at RobertKSzilagyi@gmail.com.

"Soft" Sources of Chemical Structure Information

Empirical Force Fields, Molecular Mechanics

Semi-Empirical Hamiltonians and Tight-Binding Potentials

Semi-Empirical Hamiltonians and Tight-Binding Potentials

MM FF level of theory allows for large scale computation of geometric structure information up to millions of atoms. The chemical accuracy, however, greatly dependent on the quality of the empirical parameters and the mathematical form of  potential energy functions.

Semi-Empirical Hamiltonians and Tight-Binding Potentials

Semi-Empirical Hamiltonians and Tight-Binding Potentials

Semi-Empirical Hamiltonians and Tight-Binding Potentials

The fastest quantum  chemical methods allows us to treat chemical systems with tens of thousands of atoms at a reasonable chemical accuracy and affordable computational cost. In the case of limitations in both geometric and electronic structure, we can always turn to the adjustable parameter sets and push the boundaries that this level of theory may provide. 

‘First-principle’ Quantum Methods

Semi-Empirical Hamiltonians and Tight-Binding Potentials

‘First-principle’ Quantum Methods

The ab initio level of theory can provide the highest chemical accuracy: however, at a drastically increased computational cost. The typical size of a chemical system that can be treated at this level is at most a few hundreds of atoms. When  chemical accuracy is of critical value (bond breaking/formation, redox state change, proton transfers, etc.} there is no better method than “first-principle” theory.

"Hard" Sources of Chemical Structure Information

elk

mule

elk

image1

most 'majestic' ruminant of the herd

cow

mule

elk

image2

oldies, but goodies with brains

mule

mule

bison

image3

classical look, classical performance

bison

bison

bison

image4

salvaged nodes, shine bright

sheep

bison

sheep

image5

used to serve humans

deer

bison

sheep

image6

perfect for small jobs

mammoth

xenokeryx

xenokeryx

image7

extinct, does housekeeping

xenokeryx

xenokeryx

xenokeryx

image8

extinct, still delivers