CFOUR | Main / Input Description For Calculating Vibrationally Averaged Properties

The input consist of (a) standard input for an anharmonic force-field calculation using ANH_ALGORITHM=PARALLEL together with (b) the following additional sections after the CFOUR keyword list:

In a section %anhdriv the requested properties need to be specified. Available are here NMR (required for NMR shieldings as well as spin-rotation tensors), POL (required for the polarizability tensor) JFC, JSD, and JSO (required for the various contributions of the indirect spin-spin coupling constants), EFG for the electrical field gradient, and THETA for the quadrupole tensor. Dipole momentt and dipolar coupling constants are always considered, as they do not require additional property calculations

For each property specified under %anhdriv the options for the corresponding calculations need to be specified under %nmr_keywords, %pol_keywords, %jfc_keywords, %jsd_keywords, %jso_keywords, %efg_keywords, and/or %theta_keywords in addition to the section %anh_keywords. These section allow the use of a different method and/or basis set in the property calculation compared to the anharmonic force-field calculation. For spin-rotation constants, the keywords SPINROTATION=ON need to be specified under the section %nmr_keywords. The given examples probably explain in some more detail what is required under these sections which are to be specified after the usual CFOUR keyword list.

Note that the vibrational averaging of several properties can be done simultaneously in one calculation.