(a) Do HF/6-31G* geometry optimizations on two conformers of HCOOH, one with OCOH dihedral angle of 0o and one with 180o. Compare the predicted geometries and the dipole moments of the two conformers. What is the predicted energy difference at 0 K omitting zero-point energy?
(b) Do frequency calculations on these two conformers and use scaled vibrational frequencies to get the predicted 0 K energy difference including zero-point energy. Are all the vibrational frequencies real for each conformer?