It is probably a good idea to get away from the terminology of snowflakes and/or Rydberg matter, due to the lack of specificity in meaning.
In the older paper with Miley and Hora, Holmlid called the UDD species: “Inverted Rydberg hydrogen” or IRH indicating that there is no expansive electron spacing, as expected in normal Rydberg matter. Thus, this species is technically NOT Rydberg matter unless modified to express the inverted state. To complicate things, Holmlid decided to drop the IRH terminology in favor of UDD, although Miley apparently still uses it. L. Holmlid, H. Hora, G. Miley and X. Yang, "Ultrahigh-density deuterium of Rydberg matter clusters for inertial confinement fusion targets". Laser and Particle Beams 27 (2009) 529–532. The clearest paper on this subject of like-charge attraction with dislocated electrons which are close by - could be that of Nabil Lawandy: “Interactions of charged particles on surfaces”… yet has different predictions http://scitation.aip.org/content/aip/journal/apl/95/23/10.1063/1.3270537 “Charges of the same polarity bound to a surface with a large dielectric contrast exhibit an attractive long-range Coulomb interaction, which leads to a two-particle bound state. Ensembles of like charges experience a collective long-range interaction, which results in compacted structures with interparticle separations that can be orders of magnitude smaller than the equilibrium separation of the pair potential minimum. Simulations indicate that ensembles of surface bound nuclei, such as D or T, exhibit separations small enough to result in significant rates of fusion.”
