The muon-catalyzed fusion (𝜇CF) is an established method in which D-T reactions occur at low
temperatures (at or below room) and pressure. The reduced size of diatomic muonic molecules
(say dd𝜇 or dt𝜇) allows fusion to occur due to the greatly enhanced wave-function overlap. Under
the current dMu/DT collaboration, an attempt is being made to study the 𝜇CF rate and sticking
fraction at a relatively higher temperature (but < 3 × 10^3 K) and pressure (but < 10^5 bar),
using a diamond anvil cell with D-T mixture. In parallel, physics processes related to formation,
transport, isotopic transfer, and other de-excitation processes of muonic atoms as well as 𝜇CF and
reactivation of muons to the fusion cycles are being modeled in GEANT4. This article describes
the current status of physics process modeling of 𝜇CF in GEANT4.