Editing Computational chemistry (section)

==== Computational thermochemistry ====
{{Main|Computational chemical methods in solid-state physics|Thermochemistry}}
A particularly important objective, called computational [[thermochemistry]], is to calculate thermochemical quantities such as the [[Standard enthalpy change of formation|enthalpy of formation]] to chemical accuracy. Chemical accuracy is the accuracy required to make realistic chemical predictions and is generally considered to be 1&nbsp;kcal/mol or 4&nbsp;kJ/mol. To reach that accuracy in an economic way, it is necessary to use a series of post–Hartree–Fock methods and combine the results. These methods are called [[quantum chemistry composite methods]].<ref>{{Cite journal |last1=Ohlinger |first1=W. S. |last2=Klunzinger |first2=P. E. |last3=Deppmeier |first3=B. J. |last4=Hehre |first4=W. J. |date=2009-03-12 |title=Efficient Calculation of Heats of Formation |url=https://pubs.acs.org/doi/10.1021/jp810144q |journal=The Journal of Physical Chemistry A |language=en |volume=113 |issue=10 |pages=2165–2175 |doi=10.1021/jp810144q |pmid=19222177 |issn=1089-5639}}</ref>