Alpaca-1.5.1_ps23.ccx ●

Based on the naming convention, this appears to be a input file ( .ccx extension) for a finite element analysis (FEA) model — likely named after the Alpaca example or a derivative of it, with a specific parameter set or version ( ps23 ).

It looks like you’re referring to a file named . alpaca-1.5.1_ps23.ccx