MOLPRO uses spherical harmonics (, , etc) by default, even for Pople basis sets like 6-31G**. This behaviour may be different to that of other programs; However, cartesian functions can be requested using the CARTESIAN command.
If this command is encountered, the logical MOLPRO variable CARTESIAN is set to true (1.0), and all subsequent calculations use cartesian basis functions. This is remembered across restarts. One can switch back to spherical harmonics using the command