xnn.ffnn.models.ffield.complete_off_diagonal#

xnn.ffnn.models.ffield.complete_off_diagonal(p, spec, bonds)[source]#

Fill missing off-diagonal pair parameters in place.

Applies the standard ReaxFF conventions: like pairs inherit the atomic value; unlike pairs without an explicit off-diagonal entry get the geometric-mean combination rule (or -1 when either atomic value is non-positive); and negative pi / double-pi bond radii – the ffield convention for “this pair has no pi bond” – are replaced by a fraction of the sigma radius while the corresponding bond-order exponentials are switched off (bo3/bo5 = -50, bo4/bo6 = 0).

Parameters:

p (dict) – Flat parameter dictionary, modified in place.
spec (list[str]) – Species symbols.
bonds (list[str]) – Bond types.

Return type:

None