Av_pos Av_0*(tcd.epsl/epsl_pos_0)^1.5 "Specific surface area"
eps_Li2S_s tcd.c_pce1_Li2S_s*Vm_Li2S_s "Volume fraction. Li2S(s)"
eps_S8_s tcd.c_pce1_S8_s*Vm_S8_s "Volume fraction, S8(s)"