@User try xschem option 'Simulation-> LVS netlist', this will wrap the toplevel (the inverter) in a subcircuit, as done with the layout.

I tried the same. The devices in xschem netlist seems to be recognized , but not from magic spice : New xschem netlist ** sch_path: /home/ratul619/IIT_study_VM/xschem/inv_g5D10.sch .subckt inv_g5D10 IN VSS VDD OUT *.PININFO IN:I VSS:B VDD:B OUT:O XM1 OUT IN VDD VDD sky130_fd_pr__pfet_g5v0d10v5 L=0.6 W=0.840 nf=1 ad='int((nf+1)/2) * W/nf * 0.29' as='int((nf+2)/2) * W/nf * 0.29' + pd='2*int((nf+1)/2) * (W/nf + 0.29)' ps='2*int((nf+2)/2) * (W/nf + 0.29)' nrd='0.29 / W' nrs='0.29 / W' + sa=0 sb=0 sd=0 mult=1 m=1 XM2 OUT IN VSS GND sky130_fd_pr__nfet_g5v0d10v5 L=0.6 W=0.420 nf=1 ad='int((nf+1)/2) * W/nf * 0.29' as='int((nf+2)/2) * W/nf * 0.29' + pd='2*int((nf+1)/2) * (W/nf + 0.29)' ps='2*int((nf+2)/2) * (W/nf + 0.29)' nrd='0.29 / W' nrs='0.29 / W' + sa=0 sb=0 sd=0 mult=1 m=1 .ends .GLOBAL GND .end Looping in @User , as not sure about magic spice netlist too