wavel.		cross sect.	error limit
-------------------------------------------
121.257		1.48e-19	1.1e-21
121.287		1.42e-19	1.9e-21
121.307		1.26e-19	1.5e-21
121.327		1.14e-19	1.5e-21
121.347		1.068e-19	2.1e-21
121.367		9.133e-20	1.3e-21
121.387		8.630e-20	4.1e-22
121.407		7.232e-20	8.9e-22
121.427		6.488e-20	2.6e-21
121.447		5.595e-20	3.2e-21
121.467		4.989e-20	1.9e-21
121.487		4.304e-20	2.6e-21
121.507		3.55e-20	6.0e-22
121.517		3.07e-20	1.6e-21
121.527		3.14e-20	5.2e-22
121.547		2.66e-20	7.1e-22
121.567		2.37e-20	2.3e-21