QED score for compounds

The QED score (Quantitative estimate of druglikeness) score for compounds was published by Bickerton et al 2012. To calculate this, a series of desirability functions (d) are derived, each corresponding to a different molecular descriptor. These are combined to give the QED by taking the geometric mean of the individual functions. The individual functions used are 8 widely-used molecular properties that are thought to be important for determining druglikeness:
1) molecular weight (MW)
2) octanol-water partition coefficient (ALOGP)
3) number of hydrogen bond donors (HBD)
4) number of hydrogen bond acceptors (HBA)
5) molecular polar surface area (PSA)
6) number of rotatable bonds (ROTB)
7) the number of aromatic rings (AROM)
8) number of structural alerts (ALERTS).