CCL:G: Gaussian optimization

 Sent to CCL by: "Reza  Shojaei" [shojaei81#gmail.com]
 I do optimization for Tetrahydrofuran at different levels of theory using
 different basis sets. this compound has different conformers. C1, C2, Cs
 exploiting Mp2/aug-cc-pVTZ, shows that C1 is transition state and Cs is global
 minimum. and C2 is also minimum.
 but using Mp2/aug-cc-pVDZ, Cs becomes transition state and C2 is minimum. but
 the strange thing is about C1 conformer which has no problem but checking the
 output of Gaussian shows that even starting with C1 structure as initial
 structure doesn't end to real C1 structure and the output is more similar C2.
 does anyone have any Idea, how can i get optimized structure at Mp2/aug-cc-pVDZ
 level?