  The contributed paper by Naserifar and Goddard reports that their RexPoN
water model under ambient conditions simulates liquid water as a dynamic
polydisperse branched polymer, which they speculate explains the existence of
the liquid-liquid critical point (LLCP) in the supercooled region. Our work
addresses several serious factual errors and needless speculation in their
paper about their interpretation of their model and its implication for the
LLCP in supercooled water.
