Question

Are the following statements true or false? Please explain why they are true or false.

1. Hartree-Fock self-consistent field theory can deliver the best possible wavefunction for a multielectron atom.

2. The Hartee-Fock energy is always lower than the real energy by an amount that is referred to as the correlation energy.

3. According to Variation Theory, it is possible to compute a He energy of -86.7 eV.

4. Zeff is a parameter in the exact wavefunction of He.

5. The following wavefunction would be acceptable for a 2-electron system: [f(1)g(2)][α(1)β(2)-α(2)β(1)].

6. The Born-Oppenheimer approximation permits the separation of the electronic and nuclear components of

   the wavefunction.

7. N2- is paramagnetic.

8. In HMO theory, the overlap integral assumption is accurate

Answer 1

1) Hartree-Fock self-consistent field theory can deliver the best possible wavefunction for a multielectron atom.

True : It gives the lowest possible total energy for a multi-electron system when combined into a Slater determinant and used with the complete multielectron Hamiltonian to calculate the expectation value for the total energy of the system.

2) The Hartee-Fock energy is always lower than the real energy by an amount that is referred to as the correlation energy : False

3) According to Variation Theory, it is possible to compute a He energy of -86.7 eV.

Flase : Its -77.37 ev

4) True

5)

The Born-Oppenheimer approximation permits the separation of the electronic and nuclear components of

the wavefunction

True : Born-Oppenheimer approximation shows how the electronic motions can be approximately separated from the nuclear motions

6) N2- is paramagnetic

True : As there is one unpaired electron in molecular orbital (antibonding) of N2- molecular ion

7)False , these are approximate