Models·Modeling (evaluation) is everywhere;· Assess a model:WhatYouKnow vs Howmuchyouknowaboutitgood/correct vs. costWhat Youperformanceratio;KnowUndergradEverythingMaster'sPh.D.Limit of a model;Oops! You overshot it!NothingHow muchyouALitleALotknow aboutit·Models (algorithms)are just more quantitativeextrapolation and interpolationof intuitions12
Models 12 • Modeling (evaluation) is everywhere; • Assess a model: good/correct vs. costperformance ratio; • Limit of a model; • Models (algorithms) are just more quantitative extrapolation and interpolation of intuitions
Topicsnot coveredWe can model everything!TimeYearsHoursMinutesSecondsMicrosecondsNanosecondsQuantumPicosecondsmechanics(QC)ondsDistance1A1nm1μm1mmmeters13
Topics not covered 13 We can model everything!
SimulationrelatedconceptsTheoretical chemistry. Quantum mechanics/classical mechanics basedmodels for chemical systemsComputational chemistry: Program (algorithm) + chemical systemsQuantum chemistryChemical systems explained by quantummechanics (through computation)Electronic structure calculationComputational chemistry focused on chemicalbonds (static, formation/cleavage)14
1 4 Simulation related concepts • Theoretical chemistry • Quantum mechanics/classical mechanics based models for chemical systems • Computational chemistry • Program (algorithm) + chemical systems • Quantum chemistry • Chemical systems explained by quantum mechanics (through computation) • Electronic structure calculation • Computational chemistry focused on chemical bonds (static, formation/cleavage)
Classificationofcomputational chemistryQuantum mechanics-based/Quantum chemistry Electronic structure calculation· Ab initio calculations· Semi-empirical methodsFirst-principles calculations/Density FunctionalTheory· Density Functional Tight BindingMolecularmechanics-basedMolecularmodeling/simulation (moleculardynamics, coarse-grained methods)15
15 Classification of computational chemistry • Quantum mechanics-based/Quantum chemistry ≈ Electronic structure calculation • Ab initio calculations • Semi-empirical methods • First-principles calculations/Density Functional Theory • Density Functional Tight Binding • Molecular mechanics-based • Molecular modeling/simulation (molecular dynamics, coarse-grained methods)
Plasticmolecularmodels1.Assemblefrom standard parts;2.Fixed bond lengths and coordination geometries;3.Good enough from qualitative modeling of the structure ofsome molecules;4.Easy and cheap to use;5.Provide a good feeling for the 3D structure of molecules;6.Noinformation on properties,energetics or reactivity16
Plastic molecular models 1. Assemble from standard parts; 2. Fixed bond lengths and coordination geometries; 3. Good enough from qualitative modeling of the structure of some molecules; 4. Easy and cheap to use; 5. Provide a good feeling for the 3D structure of molecules; 6. No information on properties, energetics or reactivity 16