Dear all, I have prepared a 10 node cluster (each having 4 core). I have installed GAMESS and QUANTUM ESPRESSO. Gamess is running fine, but when I run quantum espresso with the command mpiexec -n 4 ./pw.x -i relax2.in > out.out & I get no error and everything is fine. And the job run on all 4 core a single node. But when I run the same job on the 10 node with the command mpiexec -f hosts -n 40 ./pw.x -i relax2.in > out.out & I get the error mpiuser@master:~/qe-29-11/bin$ ./pw.x: error while loading shared libraries: liblapack.so.3: cannot open shared object file: No such file or directory ./pw.x: error while loading shared libraries: liblapack.so.3: cannot open shared object file: No such file or directory ./pw.x: error while loading shared libraries: liblapack.so.3: cannot open shared object file: No such file or directory However, I have "liblapack.so.3" in the same directory from where I am running the job. I sought your help. Thanking in advance. with regards Haider Abbas