User:Js8812

Monday 16th March - Tutorial 1.

a) 1,5-hexadiene (ANTI) optimisation:

Energy: -231.69253528 a.u. Symmetry: Ci

b) It is expected that gauche interactions would render the molecule less stable as there are less beneficial orbital interactions than in anti confomers. 1,5-hexadiene (GAUCHE) optimisation:

Energy: -231.69153032 a.u. Symmetry: C2

Here we get the result as expected.

c) I have found the minimum: 1,5-hexadiene (ANTI2) optimisation:

Energy: -231.69260229 a.u. Symmetry: C2

d) the structure in the appendix is the same as in (c).

e) Final energy is the same in this structure.

f) Using the new optimisation calculation:

Energy: -234.61171063 a.u. Symmetry: Ci

The sp2 bonds seem to be at a smaller angle than in the conformation calculated through the 3-21G method.

g) Calculation Performed

Sum of electronic and zero-point Energies=           -234.469219
Sum of electronic and thermal Energies=              -234.461869
Sum of electronic and thermal Enthalpies=            -234.460925
Sum of electronic and thermal Free Energies=         -234.500809