CD4051B data sheet, product information and support | TI.com
While no single "official" download exists, you can obtain functional models through community libraries and third-party archives: LTspice Community Library: LTspice Groups.io forum hosts a file named SwitchAna.lib cd4051 spice model link
Then she remembered an old mentor’s advice: “For commodity chips, check the usual suspects—Texas Instruments, NXP, and the hobbyist GitHub graveyards.” CD4051B data sheet, product information and support | TI
: The AcheronProject/acheron_ltspice repository contains a SPICE model for the SN74LV4051A CD4051B data sheet