default_refraction_coefficient value
This command defines a value that will be used for refraction coefficient codes that occur in the data file and are not specified by a refraction coefficient command.
This command affects all refraction coefficient codes except the special code "zero", which always takes the default value of 0.0.
value
Specifies the value that will be used for subsequently defined refraction coefficients. If this is not specified the value 0.075 will be used.