Which bicarbonate does not exist in solid state

The metal bicarbonates ${\mathrm{LiHCO}}_3$ does not exist in solid state. However, the metal bicarbonate ${\mathrm{NaHCO}}_3$ exist in solid state.

${\mathrm{LiHCO}}_3$ does not exist in solid state. This is because ${\mathrm{Li}}^{+}$cation has the highest hydration enthalpy. So, they do not exist in solid state.