Based on I-V curves generated in figure and the analysis of the experimental fitting results, we developed a map as shown by Figure . This map provides a summary of conditions for applying Eq 2 and Eq 3 with respect to Eq 1, and highlights the following information: 1) the first modeling method (Eq 1) has the largest scope of applicability i.e., can be applied in all conditions to examine tunneling transport; 2) The scope of applicability of the other two methods (Eq 2 and Eq 3) is jointly restricted by the potential barrier and coupling strength. We categorize our developed map in four sections. These categories are based on extent at which extracted fitting parameters varies and the difference in I-V response of the three methods. First, Eq 2 and Eq 3 did not work when coupling strength is very low (below 1 meV) at mild and low energy offset, we have seen from figure that at low coupling strength there is pronounced difference between analytical expressions and Eq 1 which hinder their performance as molecular junction single level analysis model. However, this feature under mild energy offset deliberately vanishes when coupling increases. The variation between these expressions is so small that can be ignored. Likewise, further increase in coupling make Eq 1 and Eq 2 coincide meanwhile Eq 3 well behave under low bias far from resonance. On the other hand, Eq 3 failed to be applied at low energy offset regardless of coupling strength and we also observed this from BNT molecule fitting results of Zotti et al. On the contrary, Eq 2 works appropriately under this condition when coupling is relatively strong.