\begin{table}%t4
\caption{Comparison with UMIST and Ohio State Chemical Network rate constants and their implied branching fractions\tablefootmark{a}.}
\label{udfarates}
%\centerline
{\begin{tabular}{llll}
\hline \hline
Reaction products   	&   $\alpha$			& $\beta$	&	Branch. Fract.	\\
							&	$\times$10$^{-7}$	& 				&	(\%)	\\
\hline
OSU\\
CH$_{3}$OCH$_{4}^{+}$~+~e$^-$ $\rightarrow$	\\%				&	4.50~$\times$~10$^{-7}$   	&   $-$0.50	&	100	\\
~~~~~~CH$_{3}$OCH$_{3}$+H   	&	1.50   	&   $-$0.50	&	33.3   \\
CH$_{3}$OH+CH$_{3}$   	&	1.50   	&   $-$0.50	&	33.3   \\
CH$_{3}$+ CH$_{4}$+O  	&	1.50   	&   $-$0.50	&	33.3   \\
Total							&	4.50   	&   $-$0.50	&	100	\\
\\
UMIST\\
CH$_{3}$OCH$_{4}^{+}$+e$^-$ $\rightarrow$	\\%				&	3.00~$\times$~10$^{-7}$   	&   $-$0.50	&	100	\\
~~~~~~CH$_{3}$OCH$_{3}$+H   	&   1.50   	&   $-$0.50	&	50   \\
CH$_{3}$OH+CH$_{3}$   	&   1.50   	&   $-$0.50	&	50   \\
Total							&	 3.00		&   $-$0.50	&	100	\\
\\
Current data\\
\chem{(CD_3)_2OD^+~+~e^- \rightarrow}	\\%						&	17~$\times$~10$^{-7}$	&   $-$0.70	&	100	\\
~~~~~~CH$_{3}$OCH$_{3}$+H   	&   0.85   		&	$-$0.70							&		7	\\
CH$_{3}$OH+CH$_{3}$   	&   $\leq$9.18	&  $-$0.70							&    	$\leq$49	\\
CH$_{3}$+ CH$_{4}$+O  	&   $\leq$6.97	&  $-$0.70							&		$\leq$44	\\
Total							&	17				&   $-$0.70	&	100	\\
\\
OSU\\
H$_{5}$C$_{2}$O$^{+}$~+~e$^-$ $\rightarrow$	\\%			&   7.50~$\times$~10$^{-7}$			&   $-$0.50	&	100   \\
~~~~~~CO+CH$_{4}$+H 												&   3.00   		&   $-$0.50	&	40   \\
H$_{2}$CO+CH$_{3}$   									&   1.50   		&   $-$0.50	&	20   \\
CH$_{3}$CHO+H 												&   1.50   		&   $-$0.50	&	20   \\
H$_{2}$CCO+H$_2$+H 										&   1.50   		&   $-$0.50	&	20   \\
Total											&   7.50			&   $-$0.50	&	100   \\
\\
UMIST\\
\chem{CH_3CHOH^+~+~e^-\rightarrow}	\\%					&   6.00~$\times$~10$^{-7}$			&   -0.50	&	100	\\
~~~~~~CO+CH$_{4}$+H 												&   3.00   		&   $-$0.50	&	50		\\
H$_{2}$CO+CH$_{3} $   									&   1.50   		&   $-$0.50	&	25		\\
CH$_{3}$CHO+H 											&   1.50   		&   $-$0.50	&	25		\\
Total															&   6.00		&   $-$0.50	&	100	\\
\\
Current data\\
\chem{CD_3OCD_2^+ + e^- \rightarrow}	\\%				&	17~$\times$~10$^{-7}$	&   -0.77	&	100	\\
~~~~~~CO+CH$_{4}$+H 												&   $\leq$17 	&   $-$0.77	&	$\leq$100	\\
H$_{2}$CO+CH$_{3}$   									&   $\leq$17 	&   $-$0.77	&	$\leq$100	\\
CH$_{3}$CHO+H 												&   0   									&   $-$0.77	&	0\\
H$_{2}$CCO+H$_2$+H 										&   0   									&   $-$0.77	&	0	\\
Total															&	17	&   $-$0.77	&	100	\\
\hline
\end{tabular}}
\tablefoot{\tablefoottext{a}{Rate constants are $k(T) = \alpha$*($T$/300)$^\beta$~cm$^3$~s$^{-1}$ and are compared to the product channel upper limits of the current data. Note that the exact isomers for \chem{CH_3OCH_2^+} were not found in the model databases.}} 
\vspace*{1mm}
\end{table}