Bond order analysis

Bond order analysis in ADF is activated by keyword

BONDORDER {tol=xxx} {printall}

By default bond order indices calculated by the Nalewajski-Mrozek [148-152] method are calculated. There exist three alternative definitions of the valence and bond order indices within the Nalewajski-Mrozek approach. By default the values obtained from partitioning of Tr(PΔP) are calculated and printed in the output. For more information on alternative Nalewajski-Mrozek bond order indices see Results/Properties section (5.1).

tol=xxx

The tol=xxx option specifies the threshold value for bond orders to be printed in the output (default=0.2).

printall

The values calculated from all three versions of the Nalewajski-Mrozek approach are printed when the option printall is present; in addition the Gopinathan-Jug [153] and Mayer [140] bond order indices are calculated for comparison.

Present bond order analysis is based on SFOs. Symmetry used in the calculation should be NOSYM. For this reason the analysis may be used only if the symmetry in the calculation is NOSYM. The analysis may be used also for multi-atomic fragments, the fragment-fragment bond orders are printed in such a case. Note that in the present implementation all fragment types should be different.