A multitemperature plasma emission model built on top of the apec or mekal codes. The emission measure distribution is a gaussian with mean and sigma given by the first two model parameters. The switch parameter determines whether the apec or mekal codes will be used. For the mekal code there are also the options to run the code for each temperature or interpolate from a precalculated table. The former is slower but more accurate. See the documentation on the apec model for additional information on using different AtomDB versions or applying thermal or velocity broadening.
For the gadem version, the abundance ratios are set by the abund command. The vgadem variant allows the user to define the abundances. See the documentation on the apec model for information on using additional elements included in AtomDB v2.
The parameters for gadem are:
par1 
mean temperature for gaussian emission measure distribution 
par2 
sigma temperature for gaussian emission measure distribution 
par3 
n_{H} (cm^{3}) 
par4 
abundance relative to solar 
par5 
redshift z 
par6 
0 calculate using MEKAL model 
1 interpolate using MEKAL model 

2 interpolate using APEC model 

norm 
Normalization 
For the vgadem variant the parameters are:
par1 
mean temperature for gaussian emission measure distribution 
par2 
sigma temperature for gaussian emission measure distribution 
par3 
n_{H} (cm^{3}) 
par417 
abundance relative to solar Abundances for He, C, N, O, Ne, Na, Mg, Al, Si, S,Ar, Ca, Fe, Ni wrt Solar (defined by the abund command) 
par18 
redshift z 
par19 
0 calculate using MEKAL model 
1 interpolate using APEC model 

2 interpolate using APEC model 

norm 
Normalization 