  Although experiments can offer some fingerprints of the atomic structure of
glasses (coordination numbers, pair distribution function, etc.), atomistic
simulations are often required to directly access the structure itself (i.e.,
the positions of the atoms). On the one hand, molecular dynamics (MD)
simulations can be used to generate by quenching a liquid - but MD simulations
remain plagued by extremely high cooling rates. On the other hand, reverse
Monte Carlo (RMC) modeling bypasses the melt-quenching route - but RMC often
yields non-unique glass structures. Here, we adopt the force-enhanced atomic
refinement (FEAR) method to overcome these limitations and decipher the atomic
structure of a sodium silicate glass. We show that FEAR offers an unprecedented
description of the atomic structure of sodium silicate. The FEAR-generated
glass structure simultaneously exhibits (i) enhanced agreement with
experimental neutron diffraction data and (ii) higher energetic stability as
compared to those generated by MD or RMC. This result allows us to reveal new
insights into the atomic structure of sodium silicate glasses. Specifically, we
show that sodium silicate glasses exhibit a more ordered medium-range order
structure than previously suggested by MD simulations. These results pave the
way toward an increased ability to accurately describe the atomic structure of
glasses.
