1. In the BOA, we neglect the nuclear kinetic energy
operators to solve the electronic problem.
Below is the Hamiltonian of H2+. Which are the
neglected terms?
(A)
(B)
(C)
(D) ra rb R

2. In the BOA, we neglect the nuclear kinetic energy
operators to solve the electronic problem.
Below is the Hamiltonian of H2+. Which are the
neglected terms?
(A) No, this is the electron kinetic energy operator
(B) YES!
(C) No, this is the potential energy coming from the Coulomb repulsion of the nuclei
(D) No, this is the Coulomb attraction between the nuclei and the electron ra rb R

3. In the BOA, we treat the nuclear geometry
as fixed and solve the TISE for each geometry
to get the corresponding electronic energy. In the
Hamiltonian of H2+, one term is thereby reduced
to a (nonzero) constant that does not contribute
to the electronic energy. Which one?
(A)
(B)
(C)
(D) ra rb R

4. In the BOA, we treat the nuclear geometry
as fixed and solve the TISE for each geometry
to get the corresponding electronic energy. In the
Hamiltonian of H2+, one term is thereby reduced
to a (nonzero) constant that does not contribute
to the electronic energy. Which one?
(A) The kinetic energy operator is obviously important
for electronic motion!
(B) These terms are already set to zero
(C) YES! The repulsion between the nuclei is an additive
constant that plays no role for the motion of the electrons
(D) This is the field in which the electrons move! ra rb R

5. What is the justification of the BOA?
(A) The nuclear mass is much smaller than the electron mass, so we can neglect the motion of the nuclei.
(B) The nuclear repulsion plays no role for the electron motion (see previous clicker question), so we can neglect the nuclear motion as well.
(C) The nuclear mass is much greater than that of the electrons Because the particle mass is in the denominator of the kinetic energy operator, the nuclear kinetic energy operator will be much
smaller than the electron K.E. operator.

6. What is the justification of the BOA?
(A) The nuclear mass is much smaller than the electron mass, so we can neglect the motion of the nuclei. NO! Other way around!
(B) The nuclear repulsion plays no role for the electron motion (see previous clicker question), so we can neglect the nuclear motion as well. No! This is a completely separate argument!
(C) The nuclear mass is much greater than that of the electrons Because the particle mass is in the denominator of the kinetic energy operator, the nuclear kinetic energy operator will be much
smaller than the electron K.E. operator.

7. What is the final Hamiltonian of H2+ to solve the electronic
problem within the BOA?
(A)
(B)
(C)

8. What is the final Hamiltonian of H2+ to solve the electronic
problem within the BOA?
(A)
No, this is everything we said plays no role for el. motion!
(B)
Not quite: The internuclear repulsion does not belong here.
(C)