RXMD Frequently Asked Questions

Q. I have downloaded the Linux precompiled executable and got this error message ’error while loading libraries: libmpi_usempi.so.1’. What should I do?

A. The HPC-USC tarball contains an executable build on the USC HPC environment using dynamically linked libraries (DLLs), thus it may or may not run on your computer depending on where the DLLs are installed. We are working on the executable more portable, however in the meantime, we recommend you to build the executable from source if the RXMD executable does not run on your Linux machine. Please refer to 2. How to build RXMD in RXMD User Guide.

Q. I tried to build RXMD following the user guide, but somehow it did not work. What should I do?

A. To build RXMD, you need a Fortran 2003 compiler and MPI library installed. Please email us to help.magics.software@gmail.com with 1. Fortran compiler and MPI library you have, 2. command you ran to build RXMD, 3 and all error messages you got.

Q. What are the input files for rxmd?

A. rxmd has three input files ‘rxmd.in’ defines simulation input, ‘DAT/rxff.bin’ for atom type, coordinates, and simulation box dimensions. You also need ‘ffield’ file that defines ReaxFF parameters.

Q. How many CPU can I use to run rxmd?

A. Technically as many CPU/cores as you want. rxmd is linear scalable and it has been run up to 786,432 cores that includes Linux clusters and DOE supercomputers such as IBM BlueGene/Q and Theta.