Editing Molecular modelling (section)

{{Use British (Oxford) English|date=August 2016}}
[[Image:Hardware-accelerated-molecular-modeling.png|thumb|Modeling of ionic liquid]]
{{Short description|Discovering chemical properties by physical simulations}}

'''Molecular modelling''' encompasses all methods, theoretical and computational, used to [[model (abstract)|model]] or mimic the behaviour of [[molecule]]s.<ref>{{cite book |last=Leach | first = Andrew R. | name-list-style = vanc  |title=Molecular modelling : principles and applications|date=2009|publisher=Pearson Prentice Hall|isbn=978-0-582-38210-7 |oclc=635267533}}</ref> The methods are used in the fields of [[computational chemistry]], [[drug design]], [[computational biology]] and [[materials science]] to study molecular systems ranging from small chemical systems to large biological molecules and material assemblies. The simplest calculations can be performed by hand, but inevitably computers are required to perform molecular modelling of any reasonably sized system. The common feature of molecular modelling methods is the atomistic level description of the molecular systems. This may include treating atoms as the smallest individual unit (a [[molecular mechanics]] approach), or explicitly modelling protons and neutrons with its quarks, anti-quarks and gluons and electrons with its photons (a [[quantum chemistry]] approach).