What is .spiceinit file? I can't find it in the PDK directory

ngspice claims it takes either

spinit

or

.spiceinit

although I have never figured out how to get it to work with the name

spinit

. Nevertheless, before I ran into that problem, I put it into the PDK as

spinit

. So you'll find it here:

$PDK_ROOT/sky130A/libs.tech/ngspice/spinit

Just copy it and rename it to

.spiceinit

.