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Questions tagged [expectation-values]

Questions about the calculations of expectations values (e.g. properties of a quantum mechanical system).

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9 votes
3 answers

Which expectation values can be determined with KS orbitals?

Suppose $A$ is some hermitian operator and $\Psi$ is a many body state function of a many-body hamiltonian $H = T + U + V$, where $U$ is electron-electron interaction and V is electron-nuclear ...
8 votes
2 answers

Equation (4) in Hohenberg-Kohn Paper

In their landmark paper of 1964, Inhomogeneous Electron Gas, Hohenberg and Kohn wrote down: We shall be considering a collection of an arbitrary number of electrons, enclosed in a large box and ...
5 votes
1 answer

In Molpro, how to calculate the orbital angular momentum?

I wish to calculate the values of the orbital angular momentum of excited electronic states, using Molpro. So $\langle L_x \rangle$, $\langle L_y \rangle$, and $\langle L_z \rangle$. (Specifically for ...
8 votes
1 answer

In Molpro, how do I get the two-electron operator for angular momentum from a CI calculation?

When I do a CASSCF calculation I can include the card expec2,lxx,lyy,lzz in order to calculate the two-electron operators (in the x, y, and z-directions) for ...