St9bad_alloc exception in declaring double pointer

Hi,

I am working on a C++ program where I need to work with manipulation
of large matrices. I am getting St9bad_alloc exception thrown when I
try to allocate large matrices (typically >5000x5000). However, it
works fine with smaller matrices. Is that expected or there is
anything that I can do to get rid of this? Or, if it is a memory
issue, are there better memory-saving ways to handle 2D arrays? Here
is the piece of code that's throwing error:

double *phit, *dq, **Pq, **Aq, **AqT, **dAq, **AqAqT,**IAqAqT;
    try
    {
        phit= new double[3*M];
        dq= new double[3*M];
        Pq= new double* [3*M];
        for(i=0; i<3*M; i++)
            Pq[i]=new double[3*M];
        Aq= new double*[3];
        for(i=0; i<3; i++)
            Aq[i]=new double[3*M];
        dAq= new double*[3];
        for(i=0; i<3; i++)
            dAq[i]=new double[3*M];
        AqT=new double*[3*M];
        for(i=0; i<3*M; i++)
            AqT[i]=new double[3];
        AqAqT=new double*[3];
        for(i=0; i<3; i++)
            AqAqT[i]=new double[3];
        IAqAqT=new double*[3];
        for(i=0; i<3; i++)
            IAqAqT[i]=new double[3];
    }
    catch (exception& e)
    {
        cout << "Standard exception in 3-D pointer allocation: " << e.what()
<< endl;
        exit(1);
    }

I am deallocating pointers in the standard way:
    try
    {
        for(int i=0; i<3*M; i++)
            delete[] AqT[i],Pq[i];
        for(int i=0; i<3; i++)
            delete[] Aq[i], dAq[i], AqAqT[i],IAqAqT[i];
        delete[] Aq,AqT,AqAqT,IAqAqT,Pq,phit,dq;
    }
    catch (exception& e)
    {
        cout << "Standard exception in deAllocation: " << e.what() << endl;
        exit(1);
    }

Thanks,
Vijay

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