1. In Gaussian input file, i only request %chk=xxx.chk, but does not have pop=full. Does that matter since I am only using chk file for MO visualization?
2. Do opt or TD commands lead to different MO results?
1 pop=full doesn't affect content of .chk file but only affect printed information in output file. pop=full is never needed for visualizing MOs.
2 The orbitals recorded in .chk file of TD task are exactly the same as those of ground state single point task. TD task doesn't yield new set of orbitals. Commonly, the orbitals in .chk file of opt task is identical with the orbitals generated by single point task at the final geometry.