To evaluate the performance of B3LYP-D3(BJ)/def2-SVP to calculate TEP values, we used 14 different experimental values that provide a range of donating and accepting phosphines. Table gives the experimental symmetric CO stretch values and the DFT calculated values. This comparison shows that the DFT calculated values, as expected based on the work of Clot, have a systematic error. Therefore, a simple correction factor was employed to shift the DFT values to align with the experimental values. The correction for the DFT values was determined through creating a linear regression between the uncorrected DFT TEP values and the experimental values for these seven cases. This regression had a high degree of correlation with a R 2 = 0.960. The corrected value for the CO A1 symmetric stretch frequency can be determined using Equation where vcorr is the corrected value of the Tolman electronic parameter and vuncorr is the uncorrected value.