\begin{table}%t2 \caption{\label{simline-table}Results of {\it Simline} modelling where $\alpha_2$ is the density profile exponent at the transition to the subthermal layer and X(HCO$^+$ the HCO$^+$ abundance.} %\centering \small \begin{tabular}{lcc} \hline \hline & Clump-14 & Clump-16 \\ \hline total mass & 4900 $M_{\odot}$ & 3346 $M_{\odot}$ \\ size & 0.52~pc & 0.615~pc \\ density profile ($\alpha_2$) & --8.0 & --8.0 \\ mass-averaged $T$ & 20 K & 15 K \\ $\beta$ & --0.6 & --0.5 \\ line width & 2.5~km~s$^{-1}$ & 1.5~km~s$^{-1}$ \\ $X$(HCO$^+$) & $2.5\times10^{-9}$ & $2.5\times10^{-9}$ \\ $^{12}$C/$^{13}$C & 67 & 67 \\ depletion ratio & 7 & 28 \\ % depletion density & \multicolumn{2}{c}{$1 - 8 \times 10^5 cm^{-3}$ (\textbf{$2 \times 10^5 cm^{-3}$})} \\ $\tau_{\rm HCO^+}$ & 25 & 26 \\ $\tau_{\rm H^{13}CO^+}$ & 0.81 & 0.99 \\ $v_{\rm inf}$ & --0.6~km~s$^{-1}$ & --0.5~km~s$^{-1}$ \\ \hline \end{tabular} \end{table}