This API is currently available in C++ and Python.
bool OECalculateDPI(OEIridiumData& irid, const OEChem::OEMolBase& mol)
true if the diffraction-component precision index (DPI) value can
be calculated; otherwise, it returns
false. The calculated DPI value, the
Rfree value, and the resolution of the crystal structure are stored in the
irid (an OEIridiumData object).
If the DPI is not readily readable from the PDB header data, it is calculated using the Blow equation (eq.1 in [Warren-2012]), derived from work by Blow [Blow-2002] and Cruickshank [Cruickshank-1999].