To compile the program do:
cd sofi3D/src
then
"make sofi3D"  to compile the standard staggered grid version (SSG)
(you probably need to change the compiler options in sofi3D/src/Makefile)

To run the program on 8 CPUs do
cd sofi3D/par

mpirun -np 8 ../bin/sofi3D ./in_and_out/sofi3D.json > ./in_and_out/sofi3D.jout

you may also use the shell script startSOFI3D.sh

The file sofi3D/par/in_and_out/sofi3D.jout shows the obtained screen output.

The modelling parameters are specified in sofi3D.json. I hope that the
parameters are more or less self-explanatory. The synthetic seismograms 
and snapshots are written to the files specified in :
sofi3D/par/in_and_out/sofi3D.json.

In the current distribution the model is generated on the fly by the 
function sofi3D/src/hh_elastic.c . This function generates a homogeneous
medium with Vp=3500 m/s, Vs=2000 m/s, and rho=2000 kg/(m*m*m). The function 
readmod.c can be used to read model info from external grid files. 
See readmod.c for the format of the external files. You can change the 
function which generates the model grid at the beginning of sofi3D/src/Makefile.


For more information, have a look at the SOFI3D manual which you can compile in ./sofi3D/doc/guide_sofi3D.
Additional you can find the manual at https://git.scc.kit.edu/GPIAG-Software/SOFI3D/wikis/home