Hi nam450,
I think you are referring to the generic diode. This is a fully configurable diode that's why there is no part number. You can configure the generic diode into the silicon diode that you desire. If you want a diode with part number you can search the database. However, if you are using Multisim Live using Free Subscription access, the only silicon diode available is 1N4148.
Best regards,
G. Goodwin