where Θ is the Heaviside function, |ϕ(R l (t))| is absolute value of the CNNC dihedral angle along the R l trajectory, and |ϕ 0 | = 90 • is the dividing surface that distinguishes cis and trans isomer. The details of polariton dynamics with the TSH method can also be found in our previous work performing QED dynamics with the MQC methods. 25,26