The only place in where GSL is used is in External/matvec.h

/** Eigenvalues of symmetric matrix. NOTE: This function changes the matrix M. */
inline void Eig (Mat_t & M, Vec_t & L, Mat_t * Q=NULL, bool Qtrans=false)
{
    // calculate
    size_t nrow = num_rows (M);
    size_t ncol = num_cols (M);
    if (nrow!=ncol) throw new Fatal("Eig: Matrix (%zdx%zd) must be square", nrow,ncol);

    // eigenvalues
    L.change_dim (nrow);
    gsl_vector eval = {nrow, 1, L.data, NULL, 0}; // size, stride, data, block, owner

    // solve
    gsl_matrix_view m = gsl_matrix_view_array (M.data, nrow, nrow);
    if (Q==NULL)
    {
        gsl_eigen_symm_workspace * w = gsl_eigen_symm_alloc (nrow);
        gsl_eigen_symm (&m.matrix, &eval, w);
        gsl_eigen_symm_free (w);
    }
    else
    {
        Q->change_dim (nrow, nrow);
        gsl_eigen_symmv_workspace * w = gsl_eigen_symmv_alloc (nrow);
        if (Qtrans)
        {
            gsl_matrix_view q = gsl_matrix_view_array (Q->data, nrow, nrow);
            gsl_eigen_symmv (&m.matrix, &eval, &q.matrix, w);
        }
        else
        {
            gsl_matrix * q = gsl_matrix_alloc (nrow, nrow);
            gsl_eigen_symmv (&m.matrix, &eval, q, w);
            for (size_t j=0; j<ncol; ++j)
            {
                gsl_vector_view evec_j = gsl_matrix_column (q, j);
                for (size_t i=0; i<nrow; ++i) (*Q)(i,j) = gsl_vector_get (&evec_j.vector, i);
            }
            gsl_matrix_free (q);
        }
        gsl_eigen_symmv_free (w);
    }
}

VERIFICATION CASE - HEAT TRANSFER IN A SOLID BLOCK
In order to verify the heat conduction with convection boundary conditions, a simulation model is built in
LS-DYNA® with Finite elements and in SPHriction-3D with SPH elements. The block is initially at 20°C,
and the left end is heated with a convection boundary condition. The same parameters are used in both
models. The coefficient of convection is set to 100.0 W/m2K and the external temperature is set at 500°C.
The specific heat capacity and thermal conductivity of the solid are set to 1.0 J/kgK and 3000.0 W/mK.
The simulation runs for 10.0 seconds. A graphical comparison of the results is provided in Figure 9-1.
We can see that the temperature contours and the relative magnitude of the temperature is essentially
the same in LS-DYNA® and SPHriction-3D.
Let’s take a closer look at how the temperature varies at three discrete points in the solid throughout the
simulation. We will investigate at x = 0, x = 1/2L and x = L. The results are shown in Figure 9-2, we can
see that the values obtained from SPHriction-3D agree excellently with the values obtained from LSDYNA®

https://icl.cs.utk.edu/lapack-for-windows/lapack/

VERIFICATION CASE - ELASTIC-PLASTIC TENSILE TEST
A tensile test of a cylindrical specimen will be used to evaluate the elastic-plastic algorithms in the SPH
code. A baseline case is setup and run in LS-DYNA® using finite elements, the geometry and properties
of the steel cylinder are shown in Figure 9-9.

It seems like only Particle-> is used by domain

See cuNSearch: https://github.com/InteractiveComputerGraphics/cuNSearch

HDF5-DIAG: Error detected in HDF5 (1.12.0) thread 0:
#000: D:\Luciano\Numerico\Libs\hdf5-1.12.0\src\H5Dio.c line 314 in H5Dwrite(): can't write data
major: Dataset
minor: Write failed
#1: D:\Luciano\Numerico\Libs\hdf5-1.12.0\src\H5VLcallback.c line 2186 in H5VL_dataset_write(): dataset write failed
major: Virtual Object Layer
minor: Write failed
#2: D:\Luciano\Numerico\Libs\hdf5-1.12.0\src\H5VLcallback.c line 2152 in H5VL__dataset_write(): dataset write failed
major: Virtual Object Layer
minor: Write failed
#3: D:\Luciano\Numerico\Libs\hdf5-1.12.0\src\H5VLnative_dataset.c line 207 in H5VL__native_dataset_write(): can't write data
major: Dataset
minor: Write failed
#4: D:\Luciano\Numerico\Libs\hdf5-1.12.0\src\H5Dio.c line 781 in H5D__write(): can't write data
major: Dataset
minor: Write failed

<0.0, 0.0, 0.0>
1
Hello
<0.0, 0.0, 0.0>
Hola

--------------Generating particles by AddBoxLength with defined length of particles-----------
Particle Number
5280

--------------Solving---------------------------------------------------------------
<0.0, 0.0, 0.0>
self.CellNo[0] 0
Traceback (most recent call last):
File "plate-yield.py", line 70, in
dom.Solve(1000.0,timestep,0.001,"test06",999)
File "D:\Luciano\Numerico\WeldForm\python\Domain.py", line 536, in Solve
self.CellInitiate()
File "D:\Luciano\Numerico\WeldForm\python\Domain.py", line 413, in CellInitiate
CellSize = Vec3_t ((self.TRPR(0)-self.BLPF(0))/self.CellNo[0],(self.TRPR(1)-self.BLPF(1))/self.CellNo[1],0.0)
ZeroDivisionError: float division by zero

--------------Solving---------------------------------------------------------------
Max allowable time step using CFL = 0.000285044 S
User Time Step = 0.000228035 S

Initial Condition has been generated

�[1;31mFatal: Array::operator[] (write) Subscript==45035952 (size==6859) is out of range.�[0m

Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720
Max dTdt: 720

in Thermal.cpp has been change d this:

		double m = mj/dj * 4. * ( P1->k_T * P2->k_T) / (P1->k_T + P2->k_T) * ( P1->T - P2->T) * dot( xij , GK*xij )/ (norm(xij)*norm(xij));

https://www.gnu.org/software/gsl/extras/native_win_builds.html