Generalized gradient approximation density functional theory calculati
ons at BP, B3P, BLYP and B3LYP levels coupled with a series of basis s
ets of increasing quality are presented for the six gauche conformers
of 1,2-ethanediol. The results show that the extent of the correlation
effects depends on the functional and that these methods reproduce co
rrectly the consequences of correlation. The neighboring OH group orie
nts the other OH group and this results in a preferred orientation.