  We determine the chiral constants of the Nucleon-Nucleon Two Pion Exchange
potential deduced from Chiral Perturbation Theory. By using a coarse grained
representation of the short distance interactions with 30 parameters, the
Partial Wave Analysis fit gives chi^2/dof = 1.1 to a mutually consistent set of
6713 data previously built from all published proton-proton and neutron proton
scattering data from 1950 till 2013 with LAB energy below 350 MeV. We obtain
(c1, c3, c4)=(-0.41+- 1.08,-4.66+- 0.60, 4.31+- 0.17)/GeV with an almost 100%
anti-correlation between c1 and c3. We also provide the errors in the short
distance parameters and propagate them to the deuteron properties and low
partial waves phase shifts.
