def logPdfNormal(z):
return -<NUM_LIT:0.5> * (M_LN2PI + z * z)<EOL>
Robust implementations of log pdf of a standard normal.

 @see [[https://github.com/mseeger/apbsint/blob/master/src/eptools/potentials/SpecfunServices.h original implementation]]
 in C from Matthias Seeger.