The Harkonen subflux algorithm is used to approximate the time it takes for an isochloric wave function to collapse in a closed VX system. It was discovered by Erwin Harkonen in 1974 during his most active years. The function is given as follows:
In the formula, δ is delta, g is the fixed-volume gamma function, i is interphase potential, and x is flux capacity. Although the accuracy of the approximation has been widely debated, most agree that error should be at most a few nanoseconds. VX pioneer Katherine Yalgeth estimated it to 3 nanoseconds.