[huapua21]

Hi,

When I run a molecular mechanics (MM) UFF method in order to optimize ground-state geometry in Gaussian, the calculation successfully completes however when I then open the results (.chk) file to visualize any changes changes, the molecule bond length and bond length does not change.  To test it out, I ran MM methods on simple molecules such as ethane and propane where I distorted bond angles and bond lengths drastically so that I could see if any change was occurring.  The molecule doesn't change at all using MM methods whereas when I run other methods such as HF, the geometry of the molecule changes when I open the .chk file after the calculation completes.

When I run MM methods using Spartan software however, there is a noticeable change of geometry upon successful completion of calculations.

I would also like to add (although unrelated to my previous problem) that when I try to visualize molecular orbitals in the MO tab, the graphics of the molecular orbitals are distorted and funny looking.  For example, when I look at the HOMO of H2, The "spherical" orbital that appears on the H molecules are multi-colored in a pixelized fashion and there are a few "holes" in the orbital.  These "holes" that I see in the orbital seem to be caused by some sort of problem since when I looked at the online Gaussian manual it shows molecular orbitals which do not have these "holes".  Im thinking it could be a graphics card problem?

Please note that I am a newbie at this and your help is extremely appreciated.

[BluePill]

try ArgusLab. it's much easier.