We next show the computational cost associated with the various ensemble and E-FC spectroscopy methods, accounting for the electronic structure calculations on the MD snapshots. We do not consider the computational cost from the QM/MM AIMD sampling, which is substantial, and could be accelerated with recent approaches of machine learning interatomic potentials. . The chart depicted in Figure illustrates the relative computational wall time required for the various spectroscopy methods, with average results given for simulating absorption. See Figure for the corresponding relative costs for emission, which is similar but has an increased computational cost for excited state geometry optimization for the E opt approach. Relative times are averaged over the three dyes investigated in this study. The geometry optimization and excitation energies were performed using TeraChem on a dual NVIDIA Tesla A100 PCIe v4 40GB HBM2 Passive Single GPU setup. Frequency calculations for the ground and excited states of NBD in DMSO, as well as 7MC in methanol, were carried out utilizing Gaussian16 on two Intel 28-core Xeon Gold 6330 processors, equipped with 256GB and 1TB of RAM, respectively, with the latter configuration used for the NR dye in DMSO. The E-sum 100 FTFC method is by far the most computationally demanding, taking 56.2× as long as the ensemble approach alone. Note that due to the larger QM region size for NR in DMSO, the frequency calculations are more computationally expensive, leading to a larger relative cost for the E-sum 100 FTFC approach. There is a substantial reduction in computational cost achieved through the use of more approximate methods, with the E opt -avg 10 FTFC method taking only 11.6× and the Eavg 10 ZTFC method taking only 6.7× as long as the ensemble approach. For the E opt -avg 10 FTFC approach, this decrease in computational cost comes with nearly the same accuracy as the E-sum 100 FTFC method, underscoring the efficiency of this approach and making it our recommended E-FC method for spectroscopic simulations.