what's default value in initial_spin setting in ATK?

[wot19920302]

Dear quantumwise staffs:
          when we want to calculate spin tranpsort. we should use polarized exchange correlation. Besides, we should also add initial_state block.    In vasp, as we know, if ISPIN=2,  the default value of all atoms (MAGMOM ) is 1.   So what's defalut intial_spin setting in ATK in the follwoing case:
         case 1.    polarized exchange correlation without initial_state block
         case2.    polarized exchange correlation with intial_state block(initial_spin=nospin)
         case3.    polarized exchange correlation with intial_state block(initial_spin=userspin, all atoms set 1, i.e. max net spin.)
         In my opinion,
          1.case1 should be the same with case2 because *py script of these two cases  don't have intial_spin scale.
          2.if there are default initial_spin values in ATK just like vasp, based my opinon1, case1 case2 and case3 will get teh same data
          Are my thoughts right? Looking forward to your replies.
          Best 

[Jess Wellendorff]

The InitialState object serves 2 different purposes:
1. set initial spins on atoms,
2. use a previous ground state as initial guess for the new calculation.

Case 1: if no InitialState block is used, no initial spin is specified, and ATK then defaults to maximally polarized atoms, i.e. scaled_spin=1.0. This way, ATK will automatically set up the initial spin for LSDA and SGGA if no initial spin is specified.
Case 2: with "initial_spin=nospin" in the Script Generator, you instruct ATK to use the InitialState block without setting initial spins. Should only be used for setting an initial guess from old calculation without setting initial spins.
Case 3: with scaled_spins=1.0 you get the same initial spins as the ones ATK automatically uses if none are specified, but you can of course also choose other initial spins, even spin pointing the opposite direction (up <--> down).

Your thoughts are therefore correct.

[wot19920302]

thanks for your reply, sir!