Vandhana16
You need to move the driver input section before the task line since the input is parsed sequentially.
start hexadecane
title "Hexadecane in 6-13 g basis set"
geometry units au
C 1.01239 -0.09867 -0.01056
...
end
basis
H library 6-31g
C library 6-31g
end
driver
xyz test
maxiter 200
end
task scf optimize