Table 4: Summary of variations of standard model parameters.
Parameters varied Range

1) C/O ratio 0.21-1.20

2) Metal depletion low-metal - additional depletion of real metals by factors of 2

low-metal - high-metal

3) Cosmic-ray ionization rate $\zeta$ $1.3\times10^{-18}$ s^-1- $1.3\times10^{-16}$ s^-1

4) Gas-density $n_{\rm H}$ $2\times10^3$ cm^-3- $2\times10^5$ cm^-3

5) C₃H₂ + H fraction 0.50-1.00

**Table 4:** Summary of variations of standard model parameters.
Parameters varied	Range
1) C/O ratio	0.21-1.20
2) Metal depletion	low-metal - additional depletion of real metals by factors of 2
	low-metal - high-metal
3) Cosmic-ray ionization rate $\zeta$	$1.3\times10^{-18}$ s^-1- $1.3\times10^{-16}$ s^-1
4) Gas-density $n_{\rm H}$	$2\times10^3$ cm^-3- $2\times10^5$ cm^-3
5) C₃H₂ + H fraction	0.50-1.00

Source LaTeX | All tables | In the text