# InitialSpins

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#### InitialSpins

Section States
Type block

The spin character of the initial random guesses for the spinors can be fixed by making use of this block. Note that this will not "fix" the the spins during the calculation (this cannot be done in spinors mode, in being able to change the spins is why the spinors mode exists in the first place).

This block is meaningless and ignored if the run is not in spinors mode (SpinComponents = spinors).

The structure of the block is very simple: each column contains the desired $\left< S_x \right>, \left< S_y \right>, \left< S_z \right>$ for each spinor. If the calculation is for a periodic system and there is more than one k-point, the spins of all the k-points are the same.

For example, if we have two spinors, and we want one in the $S_x$ "down" state, and another one in the $S_x$ "up" state:

%InitialSpins
0.5 | 0.0 | 0.0
-0.5 | 0.0 | 0.0
%

WARNING: if the calculation is for a system described by pseudopotentials (as opposed to user-defined potentials or model systems), this option is meaningless since the random spinors are overwritten by the atomic orbitals.

This constraint must be fulfilled:
$\left< S_x \right>^2 + \left< S_y \right>^2 + \left< S_z \right>^2 = \frac{1}{4}$

Source information

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