siesta netcdf4 file output

1) Compiling with NetCDF-4 support requires -DNCDF -DNCDF_4 pre-processor flags
2) The NetCDF-4 output files are only generated if CDF.Save is true.
3) If you want to convert a NetCDF-3 to NetCDF-4 using compression
    nccopy -d 3 -s noncompressed.nc compressed.nc
(this is also explicitly mentioned in the manual).

For further details I refer to the siesta manual.

NOTE the NetCDF-4 output files are only implemented in siesta-4.1 and above.

Thanks, I converted the DMHS.nc file to netcdf4 formate, and it was read by python-netcdf4 package. But I can found the Hamiltonian and overlap data.

It shows me like this (Maybe I goes to wrong place for getting the data):
(compressed.nc is the netcdf4 converted from dmhs.nc file)

In [9]: f = Dataset('compressed.nc')

In [10]: v = f.variables

In [11]: v['h']
Out[11]:
<type 'netCDF4._netCDF4.Variable'>
float32 h(scf_step, nspin, nnzs)
    Description: Hamiltonian (in Ry)
unlimited dimensions: scf_step
current shape = (0, 1, 749)
filling off

Does It mean nothing useful data inside or I need to deal with it further ?

Many thanks

best,
Guodong

1) Python-netcdf4 is capable of reading the DMHS.nc file even if it is a netcdf3 file. No need to bother with converting to netcdf-4
2) The stored Hamiltonian is the sparse matrix.

Thanks, maybe I don't find the right way to extract the data I want, I need to learn more about netcdf file.

Hi Nick,

I tried to read it, but I can't
the command
v['h'][:] (following the last email from me) gives array([], shape=(0, 1, 749), dtype=float32), it seems that nothing inside. Can you give me some materials to read it. Many thanks.

Best,
Guodong

Please consult the netcdf-package documentation.

However, You probably don't have SaveHS, because shape=(0,1,749) which means it isn't populated. (a size 0 means no elements).

Thanks Nick, It works now.