sw_fstat#

Syntax#

parOut = sw_fstat(state, parIn, T, E, M, nExt)

Description#

parOut = sw_fstat(state, parIn, T, E, M, nExt) calculates statistical properties of different physical variables over several sampled state. The function is called by spinw.anneal.

Input Arguments#

state

Defines the task of the function.

  • 1 Initialize the parOut structure.

  • 2 Store the parameters of the physical state.

  • 3 Calculate physical properties from the variable statistics.

parIn

Same as parOut.

T

Temperature of the system, row vector with \(n_T\) number of elements.

E

Energy of the system, row vector with \(n_T\) number of elements.

M

Magnetic moment of every atom in a matrix with dimensions of \([d_{spin}\times n_{magExt}\cdot n_T]\).

nExt

Size of the magnetic supercell, column vector of 3 integers.

kB

Boltzmann constant, units of temperature.

Output Arguments#

parOut

Output parameter structure with the following fields:

  • nStat The number of evaluated states.

  • M \(\langle M\rangle\) averaged over all magnetic moment stored in a matrix with dimensions of \([d){spin}\times n_{magExt}\cdot n_T]\).

  • M2 \(\langle M^2\rangle\) averaged over all magnetic moment stored in a matrix with dimensions of \([d){spin}\times n_{magExt}\cdot n_T]\).

  • E \(\langle E\rangle\) summed over all magnetic moment.

  • E2 \(\langle E^2\rangle\) summed over all magnetic moment.

For the final execution, the following parameters are calculated: parOut : Array of struct with \(n_T\) number of elements:

  • avgM Average components of the magnetisation over \(n_{stat}\) runs, matrix with dimensions of \([3\times n_{magExt}]\).

  • stdM Standard deviation of the mgnetisation components over \(n_{stat}\) runs, matrix with dimensions of \([3\times n_{magExt}]\).

  • avgE Average system energy per spin over \(n_{stat}\) runs, scalar.

  • stdE Standard deviation of the system energy per spin over \(n_{stat}\) runs, scalar.

  • T Final temperature of the sample.

  • Cp Heat capacity of the sample: \((\langle E^2\rangle-\langle E\rangle^2)/k_B/T^2\).

  • Chi Magnetic susceptibility of the sample: \((\langle M^2\rangle-\langle M\rangle^2)/k_B/T\).

See Also#

spinw.anneal