Hi,
there are not basis sets in the basis set library that are fitted to ECP-18, def-TZVP is an all-electron basis set, and ecp-10-mdf is the only basis set for ecp-10-mdf (relativistic Ti-ECP(MEFIT,R), Q=12, see $TURBODIR/basen/ti).
You can assign any ecp to any basis set, no matter if that is reasonable or not. In define, assign a basis set like usual. Then call
ecp "ti"and you will be asked for the name of the ECP. This is very similar to the
b "ti" command in the same define menu.
If you do not know exactly the name of the ECP, just enter
?
here, and define will search the library for ECPs of Ti. Just say
y
as soon as define shows the ECP you would like to use.
Enter
ecpl
to get a list of assigend ECPs:
ecpl
------------------------------------------------------------------------
list of effective core potentials defined yet
------------------------------------------------------------------------
no. | nickname
------------------------------------------------------------------------
1 | ti ecp-18-mhf
------------------------------------------------------------------------
Warning: The extended Hückel guess will not work any more since data for that step is only available for all-electron and ECP-10 basis sets!
Regards,
Uwe