Notation

Dirac Notation

One electron integrals

\langle p | \hat{h} | q \rangle = \int \phi^*_p(\mathbf{r}) \hat{h} \phi_q(\mathbf{r}) d\mathbf{r}

Dirac notation for two electron integrals

\langle pq | rs \rangle = \int \phi^*_p(\mathbf{r}_1) \phi^*_q(\mathbf{r}_2) \frac{1}{r_{12}} \phi_r(\mathbf{r}_1) \phi_s(\mathbf{r}_2) d\mathbf{r}_1 d\mathbf{r}_2

Mulliken notation

\left(pr|qs\right) = \int \phi^*_p(\mathbf{r}_1)\phi_r(\mathbf{r}_1) \frac{1}{r_{12}}  \phi^*_q(\mathbf{r}_2) \phi_s(\mathbf{r}_2) d\mathbf{r}_1 d\mathbf{r}_2

ERI

\langle pq||rs \rangle = \langle pq | rs \rangle - \langle pq | sr \rangle = \left(pr|qs\right) - \left(ps|qr\right)

CC Notation

Normal order

Normal ordered string

\{a^\dagger_p a_q\}

Examples:

\begin{aligned}
& \{a^\dagger_p a_q\} = a^\dagger_p a_q \\
& \{a_q a^\dagger_p\} = -a^\dagger_p a_q \\
& \{a^\dagger_p a^\dagger_q a_r a_s\} = a^\dagger_p a^\dagger_q a_r a_s \\
& \{a^\dagger_p  a_sa^\dagger_q a_r\} = -a^\dagger_p a^\dagger_q a_r a_s = a^\dagger_p a^\dagger_q a_s a_r \\
\end{aligned}

Determinant

|\Phi_0\rangle = a^\dagger_p a_q |0\rangle