Question

Conformational analysis of a molecule was performed using a global-optimisation method where the energy was evaluated using Hartree-Fock (HF) theory. The binding energy of the low-energy conformers with a host complex was then calculated using the same level of theory.

It was found that the lowest-energy conformer matched well with a known X-ray crystal structure but the binding energy with the host molecule was far too small.

(i) Define the term conformer. (ii) Explain the general principles of global optimisation of a molecule and why global optimisation is challenging to perform. (iii) Summarise the main contributions and terms that Hartree-Fock theory captures. (iv) Explain why the low-energy conformers might be reasonably modelled by HF theory. (v) Explain why HF theory fails to model the binding energy. Suggest a plausible alternative for obtaining more accurate binding energies, with comparable computational cost.

Enough detail required in answer please

Answer 1