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The torsional potential function for n ‐butane
Author(s) -
Allinger N. L.,
Profeta S.
Publication year - 1980
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540010211
Subject(s) - butane , maxima and minima , ab initio , basis set , chemistry , electronic correlation , computational chemistry , maxima , thermodynamics , potential energy , function (biology) , atomic physics , molecular physics , molecule , physics , density functional theory , mathematics , mathematical analysis , organic chemistry , art , performance art , art history , catalysis , evolutionary biology , biology
The energies of four different conformations for n ‐butane were calculated by the ab initio method using an STO‐3G basis set. Fully relaxed molecular geometries obtained from molecular mechanics (MM2) were used. The two energy minima [anti ( C 2h ), gauche ( C 2 )] and the two maxima ( C 2 , C 2v ) had the following relative energies: 0.0, 0.88, 3.56, 5.99 kcal/mole. These are approximate Hartree–Fock numbers. It is estimated that inclusion of electron correlation in the calculation would lower the last number to about 5.1 kcal/mole while leaving the first three values essentially unchanged.