[Wien] Reg: Fixed spin moment calculations

[Peter Blaha]

Step 2) is the correct thing, but at least you should also add a total 
energy for M=0.
And if the normal runsp calculation gives you the lowest total energy 
compared to all your fsm calculations, this is the proper solution.

However:   do you know   WHY   you want to make a fsm calculation ?

The  FSM method is used in 2 cases:
a) The total energy of more than ONE magnetic/non-magnetic calculations 
is almost identical. You may see this in a normal scf calculation that 
it converges very slowly (or not at all) or the calculations of runsp_c 
and runsp (zero and finite moments) give almost the same energy.
b) You obtained some solution with runsp, but you want to search for 
another (eg. a high-spin or low-spin) solution. In this case you have to 
estimate what would be the total moment of such an solution and search 
the corresponding M-range.

On 03/29/2014 01:17 PM, Peram sreenivasa reddy wrote:
> Dear WIEN2k,
>
>                      I am working on magnetic compound. For my system i
> got total magnetic moment 1.95 bohr magneton. Now i want to do fixed
> spin moment calculations.
>
>            My quires are
> 1). To do fixed spin moment calculations, first i have to initiate the
> calculations in spin polarized case after that i have to give the run
> command like "runfsm_lapw -m 1.95 -ec 0.000001".
> Is it correct way or give any suggestions?
>
> 2). To check weather this magnetic moment is correct or not i have to
> take different magnetic moment values like 0.5, 1.0, 1.5, 2.0, 2.5, 3.0.
> For all the values i have to run scf and check the total energy for each
> fsm value. After this i have to plot total energy verses magnetic moment
> values. In this plot where i get the minimum energy for a particular fsm
> value, that magnetic moment value i should have to consider.
> Is this correct procedure?
>
> Please suggest me further.
>
> Thank you very much in advance.
>
>
>
>
>
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-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
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Email: blaha at theochem.tuwien.ac.at    WWW: 
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