Matter of subnuclear density in the inner crusts of neutron stars consists
of neutron-rich atomic nuclei immersed in strongly degenerate relativistic
gas of electrons and strongly nonideal liquid of neutrons. Thermodynamic an
d kinetic properties of this matter are greatly affected by Coulomb and nuc
lear interactions and can be studied, in principle, from observations of th
ermal radiation of young (age less than or similar to 100 yr) neutron stars
.