I am running a program on 2 different machines. On one it works fine without issue. On the other it results in a segmentation fault. Through debugging, I have figured out where the fault occurs, but I can't figure out a logical reason for it to happen.

In one function I have the following code:

pass_particles(particle_grid, particle_properties, input_data, coll_eros_track, collision_number_part, world, grid_rank_lookup, grid_locations);
cout<<"done passing particles"<<endl;

The function pass_particles looks like:

void pass_particles(map<int,map<int,Particle> > & particle_grid, std::vector<Particle_props> & particle_properties, User_input& input_data, data_tracking & coll_eros_track, vector<int> & collision_number_part, mpi::communicator & world, std::map<int,int> & grid_rank_lookup, map<int,std::vector<double> > & grid_locations)
{
     //cout<<"east-west"<<endl;
    //east-west exchange (x direction)
    map<int, vector<Particle> > particles_to_be_sent_east;
    map<int, vector<Particle> > particles_to_be_sent_west;
    vector<Particle> particles_received_east;
    vector<Particle> particles_received_west;
    int counter_x_sent=0;
    int counter_x_received=0;
    for(grid_iter=particle_grid.begin();grid_iter!=particle_grid.end();grid_iter++)
    {
        map<int,Particle>::iterator part_iter;
        for (part_iter=grid_iter->second.begin();part_iter!=grid_iter->second.end();)
        {
            if (particle_properties[part_iter->second.global_part_num()].particle_in_box()[grid_iter->first])
            {
                //decide if a particle has left the box...need to consider whether particle was already outside the box 
                if ((part_iter->second.position().x()<(grid_locations[grid_iter->first][0]) && part_iter->second.position().x()>(grid_locations[grid_iter->first-input_data.z_numboxes()][0]))
                    || (input_data.periodic_walls_x() && (grid_iter->first-floor(grid_iter->first/(input_data.xz_numboxes()))*input_data.xz_numboxes()<input_data.z_numboxes()) && (part_iter->second.position().x()>(grid_locations[input_data.total_boxes()-1][0]))))
                {
                    particles_to_be_sent_west[grid_iter->first].push_back(part_iter->second);
                    particle_properties[particle_grid[grid_iter->first][part_iter->first].global_part_num()].particle_in_box()[grid_iter->first]=false;
                    counter_sent++;
                    counter_x_sent++;
                }

                else if ((part_iter->second.position().x()>(grid_locations[grid_iter->first][1]) && part_iter->second.position().x()<(grid_locations[grid_iter->first+input_data.z_numboxes()][1]))
                    || (input_data.periodic_walls_x() && (grid_iter->first-floor(grid_iter->first/(input_data.xz_numboxes()))*input_data.xz_numboxes())>input_data.xz_numboxes()-input_data.z_numboxes()-1) && (part_iter->second.position().x()<(grid_locations[0][1])))
                {
                    particles_to_be_sent_east[grid_iter->first].push_back(part_iter->second);
                    particle_properties[particle_grid[grid_iter->first][part_iter->first].global_part_num()].particle_in_box()[grid_iter->first]=false;
                    counter_sent++;
                    counter_x_sent++;
                }

                //select particles in overlap areas to send to neighboring cells
                else if ((part_iter->second.position().x()>(grid_locations[grid_iter->first][0]) && part_iter->second.position().x()<(grid_locations[grid_iter->first][0]+input_data.diam_large())))
                {
                    particles_to_be_sent_west[grid_iter->first].push_back(part_iter->second);
                    counter_sent++;
                    counter_x_sent++;
                }

                else if ((part_iter->second.position().x()<(grid_locations[grid_iter->first][1]) && part_iter->second.position().x()>(grid_locations[grid_iter->first][1]-input_data.diam_large())))
                {
                    particles_to_be_sent_east[grid_iter->first].push_back(part_iter->second);
                    counter_sent++;
                    counter_x_sent++;
                }
                ++part_iter;
            }
            else if (particles_received_current[grid_iter->first].find(part_iter->first)!=particles_received_current[grid_iter->first].end())
            {
                if ((part_iter->second.position().x()>(grid_locations[grid_iter->first][0]) && part_iter->second.position().x()<(grid_locations[grid_iter->first][0]+input_data.diam_large())))
                {
                    particles_to_be_sent_west[grid_iter->first].push_back(part_iter->second);
                    counter_sent++;
                    counter_x_sent++;
                }

                else if ((part_iter->second.position().x()<(grid_locations[grid_iter->first][1]) && part_iter->second.position().x()>(grid_locations[grid_iter->first][1]-input_data.diam_large())))
                {
                    particles_to_be_sent_east[grid_iter->first].push_back(part_iter->second);
                    counter_sent++;
                    counter_x_sent++;
                }
                part_iter++;
            }
            else
            {
                particle_grid[grid_iter->first].erase(part_iter++);
                counter_removed++;
            }
        }
    }

    world.barrier();

    mpi::request reqs_x_send[particles_to_be_sent_west.size()+particles_to_be_sent_east.size()];
    vector<multimap<int,int> > box_sent_x_info;
    box_sent_x_info.resize(world.size());
    vector<multimap<int,int> > box_received_x_info;
    box_received_x_info.resize(world.size());
    int counter_x_reqs=0;
    //send particles
    for(grid_iter_vec=particles_to_be_sent_west.begin();grid_iter_vec!=particles_to_be_sent_west.end();grid_iter_vec++)
    {
        if (grid_iter_vec->second.size()!=0)
        {
            //send a particle. 50 will be "west" tag
            if (input_data.periodic_walls_x() && (grid_iter_vec->first-floor(grid_iter_vec->first/(input_data.xz_numboxes()))*input_data.xz_numboxes()<input_data.z_numboxes()))
            {
                reqs_x_send[counter_x_reqs++]=world.isend(grid_rank_lookup[grid_iter_vec->first + input_data.z_numboxes()*(input_data.x_numboxes()-1)], grid_iter_vec->first + input_data.z_numboxes()*(input_data.x_numboxes()-1), particles_to_be_sent_west[grid_iter_vec->first]);
                box_sent_x_info[grid_rank_lookup[grid_iter_vec->first + input_data.z_numboxes()*(input_data.x_numboxes()-1)]].insert(pair<int,int>(world.rank(), grid_iter_vec->first + input_data.z_numboxes()*(input_data.x_numboxes()-1)));
            }
            else if (!(grid_iter_vec->first-floor(grid_iter_vec->first/(input_data.xz_numboxes()))*input_data.xz_numboxes()<input_data.z_numboxes()))
            {
                reqs_x_send[counter_x_reqs++]=world.isend(grid_rank_lookup[grid_iter_vec->first - input_data.z_numboxes()], grid_iter_vec->first - input_data.z_numboxes(), particles_to_be_sent_west[grid_iter_vec->first]);
                box_sent_x_info[grid_rank_lookup[grid_iter_vec->first - input_data.z_numboxes()]].insert(pair<int,int>(world.rank(),grid_iter_vec->first - input_data.z_numboxes()));
            }
        }
    }

    for(grid_iter_vec=particles_to_be_sent_east.begin();grid_iter_vec!=particles_to_be_sent_east.end();grid_iter_vec++)
    {
        if (grid_iter_vec->second.size()!=0)
        {
            //send a particle. 60 will be "east" tag
            if (input_data.periodic_walls_x() && (grid_iter_vec->first-floor(grid_iter_vec->first/(input_data.xz_numboxes())*input_data.xz_numboxes())>input_data.xz_numboxes()-input_data.z_numboxes()-1))
            {
                reqs_x_send[counter_x_reqs++]=world.isend(grid_rank_lookup[grid_iter_vec->first - input_data.z_numboxes()*(input_data.x_numboxes()-1)], 2000000000-(grid_iter_vec->first - input_data.z_numboxes()*(input_data.x_numboxes()-1)), particles_to_be_sent_east[grid_iter_vec->first]);
                box_sent_x_info[grid_rank_lookup[grid_iter_vec->first - input_data.z_numboxes()*(input_data.x_numboxes()-1)]].insert(pair<int,int>(world.rank(),2000000000-(grid_iter_vec->first - input_data.z_numboxes()*(input_data.x_numboxes()-1))));
            }
            else if (!(grid_iter_vec->first-floor(grid_iter_vec->first/(input_data.xz_numboxes())*input_data.xz_numboxes())>input_data.xz_numboxes()-input_data.z_numboxes()-1))
            {
                reqs_x_send[counter_x_reqs++]=world.isend(grid_rank_lookup[grid_iter_vec->first + input_data.z_numboxes()], 2000000000-(grid_iter_vec->first + input_data.z_numboxes()), particles_to_be_sent_east[grid_iter_vec->first]);
                box_sent_x_info[grid_rank_lookup[grid_iter_vec->first + input_data.z_numboxes()]].insert(pair<int,int>(world.rank(), 2000000000-(grid_iter_vec->first + input_data.z_numboxes())));
            }
        }
    }

    counter=0;
    for (int i=0;i<world.size();i++)
    {
        //if (world.rank()!=i)
        //{
            reqs[counter++]=world.isend(i,1000000000,box_sent_x_info[i]);
            reqs[counter++]=world.irecv(i,1000000000,box_received_x_info[i]);
        //}
    }

    mpi::wait_all(reqs, reqs + world.size()*2);

    //receive particles
    //receive west particles
    for (int j=0;j<world.size();j++)
    {
        multimap<int,int>::iterator received_info_iter;
        for (received_info_iter=box_received_x_info[j].begin();received_info_iter!=box_received_x_info[j].end();received_info_iter++)
        {
            //receive the message
            if (received_info_iter->second<1000000000)
            {
                //receive the message
                world.recv(received_info_iter->first,received_info_iter->second,particles_received_west);
                //loop through all the received particles and add them to the particle_grid for this processor
                for (unsigned int i=0;i<particles_received_west.size();i++)
                {
                    particle_grid[received_info_iter->second].insert(pair<int,Particle>(particles_received_west[i].global_part_num(),particles_received_west[i]));

                    if(particles_received_west[i].position().x()>grid_locations[received_info_iter->second][0] && particles_received_west[i].position().x()<grid_locations[received_info_iter->second][1])
                    {
                        particle_properties[particles_received_west[i].global_part_num()].particle_in_box()[received_info_iter->second]=true;

                    }
                    counter_received++;
                    counter_x_received++;
                }
            }
            else
            {
                //receive the message
                world.recv(received_info_iter->first,received_info_iter->second,particles_received_east);
                //loop through all the received particles and add them to the particle_grid for this processor
                for (unsigned int i=0;i<particles_received_east.size();i++)
                {
                    particle_grid[2000000000-received_info_iter->second].insert(pair<int,Particle>(particles_received_east[i].global_part_num(),particles_received_east[i]));
                    if(particles_received_east[i].position().x()>grid_locations[2000000000-received_info_iter->second][0] && particles_received_east[i].position().x()<grid_locations[2000000000-received_info_iter->second][1])
                    {
                        particle_properties[particles_received_east[i].global_part_num()].particle_in_box()[2000000000-received_info_iter->second]=true;

                    }
                    counter_received++;
                    counter_x_received++;
                }
            }
        }
    }

    mpi::wait_all(reqs_y_send, reqs_y_send + particles_to_be_sent_bottom.size()+particles_to_be_sent_top.size());
    mpi::wait_all(reqs_z_send, reqs_z_send + particles_to_be_sent_south.size()+particles_to_be_sent_north.size());
    mpi::wait_all(reqs_x_send, reqs_x_send + particles_to_be_sent_west.size()+particles_to_be_sent_east.size());

    cout<<"x sent "<<counter_x_sent<<" and received "<<counter_x_received<<" from rank "<<world.rank()<<endl;

    cout<<"rank "<<world.rank()<<" sent "<<counter_sent<<" and received "<<counter_received<<" and removed "<<counter_removed<<endl;
    cout<<"done passing"<<endl;
}

I only posted some of the code (so ignore the fact that some variables may appear to be undefined, as they are in a portion of the code I didn't post)

When I run the code (on the machine in which it fails), I get done passing but not done passing particles

I am lost as to what could possibly cause a segmentation fault between the end of the called function and the next line in the calling function and why it would happen on one machine and not another.