# 3.5.8 User-Defined Occupied Guess Orbitals ($occupied and$swap_occupied_virtual)

It is sometimes useful for the occupied guess orbitals to be different from the lowest $N_{\alpha}$ (or $N_{\alpha}+N_{\beta}$) orbitals. Q-Chem allows the occupied guess orbitals to be defined using the $occupied keyword. Using the$occupied input section, the user can choose which orbitals (by number) to occupy by specifying the $\alpha$-spin orbitals on the first line of the $occupied section and the $\beta$-spin orbitals on the second line. For large molecules where only a few occupied $\rightarrow$ virtual promotions are desired, it is simpler to use the$swap_occupied_virtual input section. Details can be found in Section 4.4.4.