How many samples can the program handle?

[ajogajog]

Theoretically, how many samples can the program handle?
I have a sample set, includes 14745600 samples with 55 dimensions. When I run the somoclu with multiple cores, it does not work.

Assertion failed in file src/mpi/coll/helper_fns.c at line 107: ((sendbuf)) != NULL
Assertion failed in file src/mpi/coll/helper_fns.c at line 107: ((sendbuf)) != NULL
Assertion failed in file src/mpi/coll/helper_fns.c at line 107: ((sendbuf)) != NULL
Assertion failed in file src/mpi/coll/helper_fns.c at line 107: ((sendbuf)) != NULL
Assertion failed in file src/mpi/coll/helper_fns.c at line 107: ((sendbuf)) != NULL
Assertion failed in file src/mpi/coll/helper_fns.c at line 107: ((sendbuf)) != NULL
internal ABORT - process 2
internal ABORT - process 6
internal ABORT - process 10
internal ABORT - process 14
internal ABORT - process 18
internal ABORT - process 20
tasks 2,6,10,14,18,20: Exited with exit code 1

The environment is linux, compiled by openmp. And what's interesting is that every time an even number of cores goes wrong, such as 2 4 6....
When I reduce the sample size to 9,000,000 it will work.

I found the error in this line of program:
MPI_Scatter(dataRoot, nVectorsPerRank * nDimensions, MPI_FLOAT,
data, nVectorsPerRank * nDimensions, MPI_FLOAT,
0, MPI_COMM_WORLD);

Can you help me out ?
Many thanks.