To calculate T , a coefficient in the wave function is set as B 3 = 0 , which corresponds to the fact that there is no wave incident on the potential from the right. Imposing the condition that the wave function ψ ψ ( x ) and its derivative d ψ ψ d x should be continuous at the well/barrier boundaries x = 0 and x = L , the relations between the coefficients are found, which allows T to be found as: