The calculation of nuclear shieldings are invoked by the keyword .SHIELD in the **PROPERTIES input module. Thus a complete input file for the calculation of nuclear shieldings will be:
**DALTON INPUT .RUN PROPERTIES **WAVE FUNCTIONS .HF **PROPERTIES .SHIELD *END OF INPUT
This will invoke the calculation of nuclear shieldings using London Atomic Orbitals to ensure fast basis set convergence and gauge origin independent results. The natural connection [34] is used in order to get numerically accurate results. By default the center of mass is chosen as gauge origin .
A basis set well suited for the calculation of nuclear shieldings (and indirect nuclear spin-spin coupling constants) is the TZ basis set of Ahlrichs and coworkers [42, 43] with two polarization functions [39]. This basis set is available from the basis set library as TZ2P.
Notice that a general print level of 2 or higher is needed in order to get the individual contributions (relaxation, one- and two-electron expectation values and so on) to the total nuclear shieldings.
If more close control of the different parts of the calculation of the nuclear shieldings is wanted we refer the reader to the section describing the options available. For the calculation of nuclear shieldings, these are the same as listed above for magnetizability calculations.