  Nodal line semimetals (NLSs) have attracted broad interest in current
research. In most of existing NLSs, the intrinsic properties of nodal lines are
greatly destroyed because nodal lines usually suffer sizable gaps induced by
non-negligible spin-orbit coupling (SOC). In this work,we propose the
topological nodal line electrides (TNLEs), which achieve electronic structures
of nodal lines and electrides simultaneously, provide new insight on designing
excellent NLSs nearly immune from SOC. Since the states near the Fermi level
are most contributed by nonnucleus-bounded interstitial electrons, nodal lines
in TNLEs manifest extremely small SOCinduced gap even possessing heavy
elements. Especially, we propose the family of A2B (A = Ca, Sr, Ba; B= As, Sb,
Bi) materials are realistic TNLEs with negligible SOC-induced gaps, which can
play as excellent platforms to study the intrinsic properties of TNLEs
