### Syntax for collinear calculations

Here is an example:

  4  4
1 -3  1  0
0.000000  0.000000  0.000000  0.000000 1.00
1 -3  2  0
0.000000  0.000000  0.000000  0.000000 1.00
1 -3  3  0
0.000000  0.000000  0.000000  0.000000 1.00
1 -3  4  0
0.000000  0.000000  0.000000  0.000000 1.00


First line: Number of Wannier functions, Number of bands. Here: 4,4 Now several blocks follow. One block for each Wannier function. Here 4 blocks. Each block has two lines. First line of the block: ind(nwf),lwf(nwf),mrwf(nwf),rwf(nwf). ind: Index of the atom on which the Wannier function is defined. lwf, mrwf: Specification of angular momentum. Our convention for these numbers follows the one described in the Wannier90 user guide. Here, we use (-3,1),(-3,2),(-3,3) and (-3,4), which specify four sp3 hybrid orbitals. See the Wannier90 user guide for a list of all definitions. rwf specifies the radial part of the test orbitals (trial wavefunction): For rwf = –5, the self-consistent potential Vl(r) and the energy parameters El are known. A linear combination of the ul and \dot{u}_l is constructed, with the coefficients A and B such that on the muffin-tin boundary Au_l + B\dot{u}_l is smoothly continuous with the 1s function 2(zona)2/3e-r·zona. If –4 ≤ rwf ≤ –1, the Fleur-radial wave functions with angular momentum (abs(rwf)–1) are used for all components of the test orbitals, no matter to what angular momentum they correspond. If rwf = 0, Fleur-radial wave functions with angular momentum corresponding to the angular momentum of the test orbitals are chosen. rwf=0 is usually a good choice. If 1 ≤ rwf ≤ 6, the radial hydrogen wavefunction for n=1,…,6 is used for the correct (ℓ,mℓ) If 7 ≤ rwf ≤ 12, a radial hydrogen wavefunction for n=1,…,6 is used, which is the same for all (ℓ,mℓ) components. For hybrid orbital such as sp3, t his choice might be better than 1 ≤ rwf ≤ 6. Second line of the block: alpha(nwf),beta(nwf),gamma(nwf),zona(nwf),regio(nwf). alpha,beta,gamma: Euler angles that rotate the orbitals defined in the first line of the block. zona, regio: Exact meaning depends on rwf. Zona specifies how radial and energy derivative are mixed. For hydrogen test function it specifies how fast the exponential decays.